ABOARD THE USS NORMANDY IN THE NORTH ARABIAN SEA — The captain of this warship loaded with Tomahawk missiles delivered the news to his crew: Hours earlier, the United States had killed Iran's most powerful military commander in a drone strike.

Navy Capt. Christopher D. Stone said it wasn’t clear how Iran might respond to the death of Qasem Soleimani. But the Normandy, escorting the USS Harry S. Truman near the Persian Gulf, had to be ready for anything, he said.

“We must be prepared for direct military action,” Stone recalled telling the crew.

With the warning and an elevated threat level, the sailors prepared for potential combat. Additional precautions put in place on the Normandy required them to carry flame-resistant balaclavas and gloves to complement their flame-resistant uniforms, and the Internet service they used to speak to family members was temporarily cut.

Across the region, U.S. military officials made other changes as vessels were dispatched to sea, where they would be better positioned. The Navy’s schedule for ships going into port also was altered.

The previously unreported details and interviews with more than 20 sailors on three Navy warships paint a picture of a military that was bracing for war in the wake of Soleimani’s Jan. 3 death in Baghdad. Days later, Iran launched ballistic missiles at two sites in Iraq housing U.S. troops, briefly deepening the crisis until it became clear that no Americans were killed.

The events point to a new reality: While tensions have cooled for the moment, the Pentagon is still feeling out whether Iran will retaliate again, and how.

“I have spent 26 years in this Navy not hoping for war, but preparing for war so that we can keep our nation safe,” Stone said in an interview on his warship. “I would say overwhelmingly, the response I saw was a crew that was very focused.”

After Iran’s missile attack, President Trump declared on Twitter that “all is well!” But defense officials have reported a growing number of service members who suffered mild traumatic brain injuries. As of Monday, the Pentagon said 109 had been diagnosed, with 75 treated in Iraq and returned to duty, 21 sent back to the United States and others still under evaluation in Germany.

“Our great American forces are prepared for anything,” Trump said in a televised address. “Iran appears to be standing down, which is a good thing for all parties concerned and a very good thing for the world.”

A 'shocking moment'

Aboard the Normandy, sailors watched Trump’s speech, said Navy Lt. David Remmers, who oversees weapons and is on his third deployment to the Middle East.

There was “almost an eerie feeling” afterward because the threat against U.S. forces at sea seemed to dissipate so quickly, he said. Days earlier, Remmers had told his sailors they needed to make sure the Normandy’s weapons were ready to use.

“I’ve never really spoken to anyone who has deployed to any [area of operations] that has experienced a threat warning level that we were at,” Remmers said. “My experience, speaking to other people who have been in high-tension situations, is it was the highest I had ever heard.”

Chief Warrant Officer Jordan Buck said Stone’s announcement about Soleimani was a “shocking moment.”

With 17 years in the Navy and several deployments to the Middle East, Buck said he arrived on the Normandy on Dec. 28 and “just thought it was my luck” that a crisis erupted days later. He soon began refreshing sailors on how to use life rafts.

“The threat level being elevated like it was, I had never seen that,” Buck said. “It was like a splash of cold water in the face.”

Nearby on the Truman, a 1,092-foot vessel where 5,000 Americans and dozens of fighter jets are deployed, the situation felt similar for some sailors.

Seaman Desiree Allen, who operates aviation support equipment on the carrier, said “of course I was scared” when she heard about the rising tension with Iran. One of the most challenging parts was not being able to share specifics with worried family members about what was happening, she said.

Still, she added, she knew she had a job to do and put her faith in the ship’s defenses and her fellow sailors.

“At the end of the day, the carrier is one of the most protected ships, so I felt protected,” she said. “I know what we’ve got on board, and I know they don’t have nothing on us.”

Other sailors said they managed conversations with family members when they were allowed without sharing sensitive information.

“You’ve got to compartmentalize,” said Lt. j.g. Asa Calloway, the assistant security officer on the Truman. “I talk to my wife and my father once a week, and I usually talk to them about books that we’re reading. And that’s about it.”

Navy officials declined to specify what prompted the elevated threat level or how high exactly it was, citing security concerns. They also asked The Post to withhold other specific information about the steps the Navy took in response.

Operation Sentinel

The USS Tempest, a 170-foot patrol craft, was at sea shortly after the strike on Soleimani. But Lt. Cmdr. Andre Cleveland, the commanding officer, said it has been quiet throughout his crew’s deployment.

The ship, sailing out of Bahrain, is part of a rotating fleet involved in Operation Sentinel, a mission the United States established with several partner countries last year to protect commercial vessels from Iranian attacks. The Tempest spends some time on “sentry” duty, offering security to commercial mariners while larger warships like destroyers carry out “sentinel” duty by using powerful sensors to watch for potential attacks.

On one 12-hour day at sea, the Tempest sailed dozens of miles into the Persian Gulf. Sailors briefly deployed a battery-operated Puma drone from the ship’s deck to test its abilities, practiced facing harassment from a speedboat and sailed in formation with smaller American vessels, including two Mark 6 patrol boats and two Coast Guard cutters.

Cleveland, who has been in command of the Tempest since June, said all nations have a right to sail in international waters and that the Navy is looking to de-escalate tensions. But his crew is “ready for anything,” he said.

Rear Adm. Andrew J. Loiselle, who oversees the Truman, Normandy and other ships as commander of a carrier strike group, said even at the height of the threat from Iran, the Sentinel mission continued. But he vaguely acknowledged that it changed, saying the Navy returned to the mission “almost immediately after the cessation of hostilities.”

Standing on the bridge of the Normandy, Stone watched as a succession of fighter jets landed nearby on the Truman. A single fighter jet streaked by the Normandy’s port side with a roar, its afterburners glowing in the twilight as it pulled into a climb.

“He’s just showing off for you,” Stone said with a grin.

For the moment, the seas were quiet.