The Sixth Seal Will Be On The East (Revelation 6:12)

New Evidence Shows Power of East Coast Earthquakes

Virginia Earthquake Triggered Landslides at Great Distances

Released: 11/6/2012 8:30:00 AM

“We used landslides as an example and direct physical evidence to see how far-reaching shaking from east coast earthquakes could be,” said Randall Jibson, USGS scientist and lead author of this study. “Not every earthquake will trigger landslides, but we can use landslide distributions to estimate characteristics of earthquake energy and how far regional ground shaking could occur.”

“Scientists are confirming with empirical data what more than 50 million people in the eastern U.S. experienced firsthand: this was one powerful earthquake,” said USGS Director Marcia McNutt. “Calibrating the distance over which landslides occur may also help us reach back into the geologic record to look for evidence of past history of major earthquakes from the Virginia seismic zone.”

This study will help inform earthquake hazard and risk assessments as well as emergency preparedness, whether for landslides or other earthquake effects.

The research is being presented today at the Geological Society of America conference, and will be published in the December 2012 issue of the Bulletin of the Seismological Society of America.

The USGS found that the farthest landslide from the 2011 Virginia earthquake was 245 km (150 miles) from the epicenter. This is by far the greatest landslide distance recorded from any other earthquake of similar magnitude. Previous studies of worldwide earthquakes indicated that landslides occurred no farther than 60 km (36 miles) from the epicenter of a magnitude 5.8 earthquake.

“What makes this new study so unique is that it provides direct observational evidence from the largest earthquake to occur in more than 100 years in the eastern U.S,” said Jibson. “Now that we know more about the power of East Coast earthquakes, equations that predict ground shaking might need to be revised.”

It is estimated that approximately one-third of the U.S. population could have felt last year’s earthquake in Virginia, more than any earthquake in U.S. history. About 148,000 people reported their ground-shaking experiences caused by the earthquake on the USGS “Did You Feel It?” website. Shaking reports came from southeastern Canada to Florida and as far west as Texas.

In addition to the great landslide distances recorded, the landslides from the 2011 Virginia earthquake occurred in an area 20 times larger than expected from studies of worldwide earthquakes. Scientists plotted the landslide locations that were farthest out and then calculated the area enclosed by those landslides. The observed landslides from last year’s Virginia earthquake enclose an area of about 33,400 km2, while previous studies indicated an expected area of about 1,500 km2 from an earthquake of similar magnitude.

“The landslide distances from last year’s Virginia earthquake are remarkable compared to historical landslides across the world and represent the largest distance limit ever recorded,” said Edwin Harp, USGS scientist and co-author of this study. “There are limitations to our research, but the bottom line is that we now have a better understanding of the power of East Coast earthquakes and potential damage scenarios.”

Learn more about the 2011 central Virginia earthquake.

Iran Increases the Length of Her Nuclear Horn (Daniel 8:4)

Iran Says It Launched a Military Satellite Into Orbit

The announcement by the Islamic Revolutionary Guards Corps could not immediately be confirmed. The U.S. says such launches advance Iran’s missile program.

By The Associated PressApril 10, 2020

TEHRAN — The Islamic Revolutionary Guard Corps of Iran said on Wednesday that it had put a military satellite into orbit for the first time, a surprise launch that came amid wider tensions with the United States.

The launch of the satellite, which the Guard called “Noor,” or light, has not been independently confirmed. The State Department and the Pentagon did not immediately respond to requests for comment.

The announcement raised concerns among experts about whether the technology used to launch the satellite could help Iran develop intercontinental ballistic missiles.

Iran has already abandoned all limitations on its tattered nuclear deal with world powers that President Trump unilaterally withdrew America from in 2018. Mr. Trump’s decision set off a monthslong series of escalating attacks that culminated in a U.S. drone strike in January that killed a top Iranian general in Iraq.Iran countered by firing ballistic missiles at American soldiers in Iraq.

For Iran, which is already dealing with the coronavirus outbreak, a struggling economy and historically low oil prices, the missile launch may signal a new willingness to take risks. At home, Iran, which was initially overwhelmed by the coronavirus, is seeking to sway international opinion on U.S. sanctions by highlighting its struggles with the coronavirus outbreak. In Iran, the regional epicenter of the outbreak, the virus has killed more than 5,290 people, from among over 84,800 reported cases.

“This raises a lot of red flags,” said Fabian Hinz, a researcher at the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies in Monterey, Calif. “Iran doesn’t have that much to lose anymore,” he added, referring to the United States’ “maximum pressure” campaign, a series of sanctions imposed against crucial industries and top officials.

On its official website, the Guards called it the first military satellite ever launched by Tehran and said the satellite had reached an orbit of 425 kilometers, about 265 miles, above the Earth’s surface.

The three-stage satellite launch took off from Iran’s Central Desert, the Guards said, without elaborating.

Mr. Hinz said, based on state media images, the launch appeared to have happened at a previously unnamed Guard base near Shahroud, Iran, about 200 miles northeast of Tehran. The base is in Semnan Province, the site of the Imam Khomeini Spaceport, from which Iran’s civilian space program operates.

The paramilitary force said it used a Ghased, or “Messenger,” satellite carrier to launch the device into space — a previously unheard-of system. it described as using both liquid and solid fuel.

“Today, the world’s powerful armies do not have a comprehensive defense plan without being in space, and achieving this superior technology that takes us into space and expands the realm of our abilities is a strategic achievement,” said Gen. Hossein Salami, the head of the Guards.

Wednesday is the 41st anniversary of the founding of the Guards by the former Iranian leader Ayatollah Ruhollah Khomeini. An image of the rocket that carried the satellite showed it bore a Quranic verse that is typically recited when going on a journey.

The Guards, which operate their own military infrastructure parallel to Iran’s regular armed forces, is a hard-line organization answerable only to the supreme leader, Ayatollah Ali Khamenei.

It was not immediately clear whether Iran’s civilian government was told of the launch in advance. President Hassan Rouhani gave a nearly 40-minute speech on Wednesday before his cabinet and did not mention it.

Save the Oil But Not the Wine (Revelation 6:6)

Oil Rebounds After Trump Signals Fresh Iran Tensions

The recent fall in the value of oil has reverberated across energy markets, hitting the value of oil companies

By David Hodari and Caitlin Ostroff

Updated April 22, 2020 3:31 pm ET

Crude prices rose Wednesday, pausing a weekslong crash after President Trump warned Iran that he has instructedthe U.S. Navy to destroy Iranian gunboats if they continue to harass American ships in the Persian Gulf.

U.S. crude-oil futures for delivery in June rose 19% to $13.78 a barrel, extending a series of chaotic moves. The most heavily traded U.S. crude benchmark on Tuesday collapsed to a 21-year low, with supply overwhelming demand and storage in many parts of the world full.

On Monday, a U.S. crude futures contract turned negative for the first time ever, effectively meaning sellers were paying buyers to take away oil due to a lack of storage. The contract that turned negative early in the week expired in positive territory on Tuesday.

Brent crude futures, the global benchmark for oil markets, climbed 5.4% to $20.37 a barrel on Wednesday but also remained near a multidecade low.

The president’s warning on Twitter to Iran helped spur the gains and followed recent encounters between U.S. ships and Iranian vessels. The possibility of tension in the region can boost oil prices by signaling potential disruptions to shipments of oil around the world and possible supply shortages.

Still, many analysts expect the glut of crude that has collapsed prices to persist due to the coronavirus pandemic.

“It’s a geopolitical piece of news that has lifted the price at a time when the market has been heavily sold,” said Ole Hansen, head of commodity strategy at Saxo Bank.

That came two days after one WTI contract turned negative for the first time in history, with sellers paying buyers to take away their barrels.

While benchmark oil-futures prices have collapsed this week, the price of a physical barrel of oil is even lower. A real-life barrel of Brent crude oil cost $13.24 late Tuesday, its lowest price since March 1999, according to S&P Global Platts. Physical prices in some parts of the U.S. have recently turned negative.

This week’s crushing fall in the value of oil has reverberated across energy markets, hitting the value of oil companies and the debt they issue. If oil prices stay at such a low level, the loss of revenue is likely to create widespread financial and political pain for countries reliant on petroleum production.

Government measures keeping billions of citizens at home in an attempt to stymie the spread of the coronavirus have decimated oil demand. Compounding the problem was a massive overproduction of crude during a price war last month between Saudi Arabia and Russia.

The two sides have called a truce, but now the world is essentially swimming in oil that nobody needs. Some oil producers have been reluctant to shut down because doing so quickly could cause long-term damage to their wells.

Storage capacity has appeared to reach its limit, prompting this week’s massive selloff.

“We could see unexpected methods of storage coming into play if they can’t store it in the traditional pipeline system,” said Richard Fullarton, founder of London-based private fund manager Matilda Capital Management Ltd. “They may have to store it in on-land pond facilities or cap a whole tranche of wells.”

Industry data have underscored the massive oversupply. Government figures Wednesday showed U.S. stockpiles rose 15 million barrels last week, extending a recent stretch of sizable increases.

Free commercial oil storage capacity has dwindled to around 130 million barrels out of an estimated 1.38 billion barrels of space, according to cargo tracker Kpler, although logistical bottlenecks mean not all that capacity can be used.

The shock to oil prices has reverberated through broader markets, sending stocks of oil producers down. Debt issued by energy companies also has sold off sharply, indicating the rising risk of a wave of defaults, something that could affect other high-yield borrowers, said Seema Shah, chief strategist at Principal Global Investors. U.S. oil companies are among some of the largest issuers, making up about 12% of high-yield bond indexes.

“With oil prices so low, they are going to be under so much pressure right now that you almost have a contagion effect from energy to high yield,” she said.

Shares of energy producers also rebounded Wednesday, with some large companies like BP PLC rising 5% or more.

“There’s a very significant contrast between low oil prices and high equity prices, and I think this has been a reminder that we’re not in the clear yet,” Ms. Shah said. “At least in the short term oil prices are going to be under pressure,” she said.

The drop in prices will most hurt countries that depend on oil for much of their revenue, according to Chris Turner, head of foreign-exchange strategy at ING Bank. Countries including Iraq and Bahrain rely on oil for most their revenue, according to an ING analysis.

The Forces Fueling 2020’s Oil Bust

The coronavirus has stalled factories and shut down business around the world, causing a historic drop in oil demand just as production was reaching new highs.

—Joe Wallace and Amrith Ramkumar contributed to this article.

Write to David Hodari at David.Hodari@dowjones.com and Caitlin Ostroff at caitlin.ostroff@wsj.com

The Ten Nuclear Horns of Prophecy (Daniel 7)

Why China’s Alleged Nuclear Testing Makes Case for Ratifying the Test Ban Treaty

On April 15th, the U.S. Department of State released a report questioning China’s compliance with its moratorium on nuclear testing. It says activity atChina’s nuclear weapons test site and a lack of transparency about those activities “raise concerns” about China’s adherence to the terms of the Comprehensive Nuclear Test Ban Treaty. 

China and the United States, along with Russia, the United Kingdom and France, agreed not to conduct nuclear weapons tests banned by the treaty even though it has yet to enter into force. Russia, the United Kingdom, France and 165 other nations have ratified the treaty. China and the United States, along with North Korea, Egypt, Iran, India, Israel, and Pakistan have not. Those eight hold-outs must ratify the treaty before the full provisions of the CTBT can take effect.

Those provisions include comprehensive verification measures.If the CTBT were in effect today the concerns in the compliance report could be investigated through on-site inspections. China has repeatedly told the United States it will ratify the CTBT as soon as it has a chance to review any reservations the U.S. Senate might attach to America’s ratification vote. China’s been waiting for twenty-four years. The United States and China both signed the CTBT in 1996, but the one and only senate vote on ratification in October 1999 failed to muster the required two-thirds in favor.

How to Respond

Some U.S. senators argue the United States should respond to these new concerns about Chinese test site activity by withdrawing the U.S. signature from the CTBT and resuming testing. That’s a bad idea. China has far more to gain from renewed explosive nuclear testing than the United States.

China was only able to conduct 45 explosive nuclear weapons tests before signing the test ban treaty and agreeing to the voluntary moratorium; in comparison, the United States conducted 1,056 tests. This enormous U.S.–China testing gap is a considerable U.S. advantage. Preserving the test ban preserves that advantage.

Each nuclear test provides weapons designers with valuable data. But there are diminishing returns as testing continues. Chinese designers barely gained enough information from their limited testing program to reduce the mass of China’s nuclear warheads to a point where they could fit one each on China’s new road-mobile and submarine-launched ballistic missiles. Additional testing could help China further reduce the mass of its warheads, making it easier for China to put multiple warheads on its missiles. It would also allow China to produce a greater number of warheads from its limited supply of weapons-grade plutonium.

These two critical Chinese advances would vastly outweigh any benefits the United States might gain from a resumption of explosive nuclear testing. Keeping the moratorium in place and verifying Chinese compliance using the robust provisions of the CTBT would keep Americans safer.

Transparency and Trust

The United States and the rest of the world should ask questions about what China is doing at its nuclear test site in Lop Nor. But it may be no more than what the United States is doing at its test site in Nevada, where, to borrow the phrasing of the U.S compliance report on China, the U.S. nuclear weapons labs are “maintaining a high level of activity” and operating the Nevada test site “year round.”

Back in the 1990s, when China and the United States were negotiating the CTBT and considering ratification, the Chinese and U.S. nuclear weapons laboratories engaged in modest but regular exchanges that maintained confidence in their respective efforts to end testing. Had those exchanges continued, current U.S. questions about Chinese compliance and the work China is doing at Lop Nor might be a lot easier to answer.

This kind of transparency, which the compliance report rightfully notes is lacking, requires a modicum of mutual trust. Unfortunately, U.S.-China relations have deteriorated to the point where neither side is willing to engage the other on nuclear weapons issues. As a result, mutual suspicion and accusation are filling the void left by the lack of constructive dialog.

Arms Racing and Arms Control

Both China and the United States know from past experience that mutual suspicion fuels arms racing. Under its influence, the quest for balance and stability gives way to the search for advantage. U.S. and Chinese leaders are well aware that public accusations, like the one insinuated in the U.S. compliance report, increase acrimony and discourage dialog, especially when they’re unfounded. Left unchecked, mutual suspicion and repeated accusations will lock both nations into a negative spiral that will require extraordinary effort to escape.

China and the United States also know the search for military advantage, especially in nuclear armaments, is always fruitless. Every measure taken to gain a temporary advantage eventually produces a countermeasure to negate it. This is the reality on which nuclear arms control is based.

Dr. Gregory Kulacki is the China Program Manager at the Union of Concerned Scientists. Follow him on Twitter @gkucs.

Image: Reuters.

Israel Infiltrates Outside the Temple Walls (Revelation 11)

Israeli military infiltrates southern Gaza border, raze land

RAFAH, Wednesday, April 22, 2020 (WAFA) – Israeli military vehicles infiltrated this morning the southern Gaza Strip border near the city of Rafah and razed land, reported WAFA correspondent.

He said six military vehicles breached the border east of Rafah and razed land while shooting in the air, before returning to their base inside Israel.

T.R./M.K.

Why We Are In Trouble At The Sixth Seal (Revelation 6:12)

Why NRC Nuclear Safety Inspections are Necessary: Indian Point

Dave Lochbaum

This is the second in a series of commentaries about the vital role nuclear safety inspections conducted by the Nuclear Regulatory Commission (NRC) play in protecting the public. The initial commentary described how NRC inspectors discovered that limits on the maximum allowable control room air temperature at the Columbia Generating Station in Washington had been improperly relaxed by the plant’s owner. This commentary describes a more recent finding by NRC inspectors about animproper safety assessment of a leaking cooling water system pipe on Entergy’s Unit 3 reactor at Indian Point outside New York City.

Indian Point Unit 3: Leak Before Break

On February 3, 2017, the NRC issued Indian Point a Green finding for a violation of Appendix B to 10 CFR Part 50. Specifically, the owner failed to perform an adequate operability review per its procedures after workers discovered water leaking from a service water system pipe.

On April 27, 2016, workers found water leaking from the pipe downstream of the strainer for service water (SW) pump 31. As shown in Figure 1, SW pump 31 is one of six service water pumps located within the intake structure alongside the Hudson River. The six SW pumps are arranged in two sets of three pumps. Figure 1 shows SW pumps 31, 32, and 33 aligned to provide water drawn from the Hudson River to essential (i.e, safety and emergency) components within Unit 3. SW pumps 34, 35, and 36 are aligned to provide cooling water to non-essential equipment within Unit 3.

Fig. 1 (Source: Nuclear Regulatory Commission Plant Information Book) (click to enlarge)

Each SW pump is designed to deliver 6,000 gallons of flow. During normal operation, one SW pump can handle the essential loads while two SW pumps are needed for the non-essential loads. Under accident conditions, two SW pumps are needed to cool the essential equipment. The onsite emergency diesel generators can power either of the sets of three pumps, but not both simultaneously. If the set of SW pumps aligned to the essential equipment aren’t getting the job done, workers can open/close valves and electrical breakers to reconfigure the second set of three SW pumps to the essential equipment loops.

Because river water can have stuff in it that could clog some of the coolers for essential equipment, each SW pump has a strainer that attempts to remove as much debris as possible from the water. The leak discovered on April 27, 2016, was in the piping between the discharge check valve for SW pump 31 and its strainer. An arrow points to this piping section in Figure 1. The strainers were installed in openings called pits in the thick concrete floor of the intake structure. Water from the leaking pipe flowed into the pit housing the strainer for SW pump 31.

The initial leak rate was modest—estimated to be about one-eighth of a gallon per minute. The leak was similar to other pinhole leaks that had occurred in the concrete-lined, carbon steel SW pipes. The owner began daily checks on the leakage and prepared an operability determination. Basically, “operability determinations” are used within the nuclear industry when safety equipment is found to be impaired or degraded. The operability determination for the service water pipe leak concluded that the impairment did not prevent the SW pumps from fulfilling their required safety function. The operability determination relied on a sump pump located at the bottom of the strainer pit transferring the leaking water out of the pit before the water flooded and submerged safety components.

The daily checks instituted by the owner included workers recording the leak rate and assessing whether it had significantly increased. But the checks were against the previous day’s leak rate rather than the initial leak rate. By September 18, 2016, the leakage had steadily increased by a factor of 64 to 8 gallons per minute. But the daily incremental increases were small enough that they kept workers from finding the overall increase to be significant.

The daily check on October 15, 2016, found the pump room flooded to a depth of several inches. The leak rate was now estimated to be 20 gallons per minute. And the floor drain in the strainer pit was clogged (ironic, huh?) impairing the ability of its sump pump to remove the water. Workers placed temporary sump pumps in the room to remove the flood water and cope with the insignificantly higher leak rate. On October 17, workers installed a clamp on the pipe that reduced the leakage to less than one gallon per minute.

The operability determination was revised in response to concerns expressed by the NRC inspectors. The NRC inspectors were not satisfied by the revised operability determination. It continued to rely on the strainer pit sump pump removing the leaking water. But that sump pump was not powered from the emergency diesel generator and thus would not remove water should offsite power become unavailable. Step 5.6.4 of procedure EN-OP-14, “Operability Determination Process,” stated “If the Operability is based on the use or availability of other equipment, it must be verified that the equipment is capable of performing the function utilized in the evaluation.”

The operability determination explicitly stated that no compensatory measures or operator manual actions were needed to handle the leak, but the situation clearly required both compensatory measures and operator manual actions.

The NRC inspectors found additional deficiencies in the revised operability determination. The NRC inspectors calculated that a 20 gallon per minute leak rate coupled with an unavailable strainer pit sump pump would flood the room to a depth of three feet in three hours. There are no flood alarms in the room and the daily checks might not detect flooding until the level rose to three feet. At that level, water would submerge and potentially disable the vacuum breakers for the SW pumps. Proper vacuum breaker operation could be needed to successfully restart the SW pumps.

The NRC inspectors calculated that the 20 gallon per minute leak rate without remediation would flood the room to the level of the control cabinets for the strainers in 10 hours. The submerged control cabinets could disable the strainers, leading to blocked cooling water flow to essential equipment.

The NRC inspects calculated that the 20 gallon per minute leak rate without remediation would completely fill the room in about 29 hours, or only slightly longer than the daily check interval.

Flooding to depths of 3 feet, 10 feet, and the room’s ceiling affected all six SW pumps. Thus, the flooding represented a common mode threat that could disable the entire service water system. In turn, all safety equipment shown in Figure 2 no longer cooled by the disabled service water system could also be disabled. The NRC estimated that the flooding risk was about 5×10-6 per reactor year, solidly in the Green finding band.

Fig. 2 (Source: Nuclear Regulatory Commission Plant Information Book) (click to enlarge)

UCS Perspective

“Leak before break” is a longstanding nuclear safety philosophy. Books have been written about it (well, at least one report has been written and may even have been read.)  The NRC’s approval of a leak before break analysis can allow the owner of an existing nuclear power reactor to remove pipe whip restraints and jet impingement barriers. Such hardware guarded against the sudden rupture of a pipe filled with high pressure fluid from damaging safety equipment in the area. The leak before break analyses can provide the NRC with sufficient confidence that piping degradation will be detected by observed leakage with remedial actions taken before the pipe fails catastrophically. More than a decade ago, the NRC issued a Knowledge Management document on the leak before break philosophy and acceptable methods of analyzing, monitoring, and responding to piping degradation.

This incident at Indian Point illustrated an equally longstanding nuclear safety practice of “leak before break.” In this case, the leak was indeed followed by a break. But the break was not the failure of the piping but failure of the owner to comply with federal safety regulations. Pipe breaks are bad. Regulation breaks are bad. Deciding which is worse is like trying to decide which eye one wants to be poked in. None is far better than either.

As with the prior Columbia Generating Station case study, this Indian Point case study illustrates the vital role that NRC’s enforcement efforts plays in nuclear safety. Even after NRC inspectors voiced clear concerns about the improperly evaluated service water system pipe leak, Entergy failed to properly evaluate the situation, thus violating federal safety regulations. To be fair to Entergy, the company was probably doing its best, but in recent years, Entergy’s best has been far below nuclear industry average performance levels.

The NRC’s ROP is the public’s best protection against hazards caused by aging nuclear power reactors, shrinking maintenance budgets, emerging sabotage threats, and Entergy.Replacing the NRC’s engineering inspections with self-assessments by Entergy would lessen the effectiveness of that protective shield.

The NRC must continue to protect the public to the best of its ability. Delegating safety checks to owners like Entergy is inconsistent with that important mission.

Support from UCS members make work like this possible. Will you join us? Help UCS advance independent science for a healthy environment and a safer world.

Trump Promises to Gun Down the Iranian Horn

Trump Says He Told Navy to ‘Shoot Down’ Iranian Boats, as Tehran Launches Military Satellite

By Helene Cooper, Eric Schmitt, Lara Jakes and Thomas Gibbons-Neff

April 22, 2020

The president’s statement came a week after the Pentagon accused Iran of sending 11 fast boats to conduct “dangerous and harassing approaches” to six American warships in the Persian Gulf, and Tehran for the first time launched a military satellite.

WASHINGTON — President Trump said on Wednesday that he has told the Navy to “shoot down and destroy” any Iranian fast boats that harass American naval ships, in what would be a sharp escalation of the risky maneuvers performed by the two adversaries in the Persian Gulf and the Arabian Sea.

The president’s abrupt statement, which he announced on Twitter, came on the morning that Iran successfully launched a military satellite and a week after the Pentagon accused Iran of sending 11 fast boats to conduct “dangerous and harassing approaches” to six American warships in the Persian Gulf.

Secretary of State Mike Pompeo confirmed the satellite launch and demanded that the United Nations Security Council hold Iran accountable for the potential violation of international guidelines restricting Tehran’s nuclear-capable missile program.

He noted that the government in Tehran had previously claimed that its missile launches were linked to commercial efforts — and not to its military, as it did Wednesday.

“I think today’s launch proves what we’ve been saying all along here in the United States,” Mr. Pompeo told reporters at the State Department. He noted that the launch was carried out by Iran’s Islamic Revolutionary Guards Corps, which has been designated by the State Department as a terrorist organization.

In the encounter last week with American warships, a swarm of Iranian fast boats, according to the Defense Department, “repeatedly crossed the bows and sterns” of the Navy ships at high speed, coming within 10 yards of one ship.

Mr. Trump did not say anything when the episode took place last week; such maneuvers have occurred for years, as American warships ply the Persian Gulf near Iranian territorial waters and Iran shows its ire by sending fast boats to harass the ships. Usually, the incidents end with warnings from the Pentagon.

But Mr. Trump on Wednesday suddenly escalated the potential American response, in a tweet that seemed to catch the Pentagon by surprise. “I have instructed the United States Navy to shoot down and destroy any and all Iranian gunboats if they harass our ships at sea,” he wrote on Twitter.

The Navy referred all questions to the White House. A Defense Department official said that the service had not received any formal policy directive from Mr. Trump ordering the Navy to start shooting Iranian gunboats. A U.S. military official said that there have been no further incidents with the Iranians, fast boats or otherwise, since the one last week.

Speaking to reporters Wednesday, David L. Norquist, the deputy defense secretary, said Mr. Trump’s statement on Twitter was more of a warning to the Iranians than a change to the current rules of engagement.

“The president issued an important warning to the Iranians, what he was emphasizing is that all of our ships retain the right of self-defense,” Mr. Norquist said. “The president is describing and responding to poor behavior of the Iranians.”

Standing alongside Mr. Norquist, Gen. John E. Hyten, the vice chairman of the Joint Chiefs of Staff, said that he liked “that the president warned an adversary.”

The president has a history of Twitter announcements that seem at odds with traditional policy, including that involving the military and its rules and operations.

American military units on the ground and at sea abide by strict rules on “escalation of force,” a ladder that includes audible warnings, flares and maneuvers before a shot is fired, often as a last measure.

Mr. Trump’s directive, in many ways, discounts this entire process and could lead to injury and death on an already crowded, and often confusing, waterway such as the Persian Gulf.

General Hyten declined to comment on the results of the Iranian missile test, citing classified intelligence.

“I won’t go into those details but it went a very long way which means it has the ability, once again, to threaten their neighbors, our allies,” General Hyten said. “This is just another example of Iranian malign behavior and it goes right along with the harassment from the fast boats.”

The Navy released video of last week’s naval incident, which showed fast boats zooming close to an American warship. “He’s taking a bow,” one American voice is overheard saying, as one Iranian boat circles the ship.

Former American commanders in the Middle East said on Wednesday that U.S. Navy officers were already well trained in dealing with the ebb and flow of Iran’s naval harassment, and did not need new directives from Mr. Trump.

“Commanders are well aware and already have sufficient guidance to deal with these types of events,” said Vice Adm. John W. Miller, a retired commander of the Fifth Fleet, based in Bahrain.

Tensions between the United States and Iran have been high for more than a year, and the coronavirus crisis has not ushered in any easing.

The Trump administration has continued to impose its “maximum pressure” campaign of economic sanctions against Tehran after the United States withdrew from an international nuclear agreement; Tehran for its part has launched proxy attacks against American troops, interests and allies in the region.

Iran’s Islamic Revolutionary Guards Corps, which commands the fast boats, is a paramilitary organization, separate from Iran’s conventional military. The Revolutionary Guard Corps carry out operations across the Middle East, train Arab Shiite militias and oversee businesses in Iran.

The Trump administration last April designated the Revolutionary Guards as a foreign terrorist organization, the first time that the United States named part of another nation’s government as that type of official threat.

In January, American drones killed Qassim Suleimani, a top Iranian general who headed the Quds Force, an elite unit of the Revolutionary Guards, drastically escalating tensions between Washington and Tehran.

More on the United States and Iran

Helene Cooper is a Pentagon correspondent. She was previously an editor, diplomatic correspondent and White House correspondent, and was part of the team awarded the 2015 Pulitzer Prize for International Reporting, for its coverage of the Ebola epidemic. @helenecooper

Eric Schmitt is a senior writer who has traveled the world covering terrorism and national security. He was also the Pentagon correspondent. A member of the Times staff since 1983, he has shared three Pulitzer Prizes. @EricSchmittNYT

Lara Jakes is a diplomatic correspondent based in the Washington bureau of The New York Times. Over the past two decades, Ms. Jakes has reported and edited from more than 40 countries and covered war and sectarian fighting in Iraq, Afghanistan, Israel, the West Bank and Northern Ireland. @jakesNYT

Thomas Gibbons-Neff is a reporter in the Washington bureau and a former Marine infantryman. @tmgneff