The Trump administration is working to drum up support for its claim that Iran launched a dawn attack on two tankers in the Gulf of Oman Thursday.

Reuters reported on Saturday that Defense Secretary Patrick Shanahan is considering sending “more troops and military capacities to the Middle East,” though it’s unclear if that means more ships in the Persian Gulf, or bombers and troops to U.S. bases in Qatar and other Gulf Arab countries.

Shanahan said that the United States is trying to build consensus on what to do next, adding that the Pentagon is “always planning various contingencies.”

But the worry is that those contingencies, which could be seen as a military escalation by Iran and other regional actors, might inadvertently lead to a conflict that could spread throughout the region.

As early as Thursday afternoon — hours after the incident —  the Trump administration was blaming Iran for the strikes on the two ships. The Norwegian-owned Front Altair was loaded with naphtha, a flammable oil, and the Japanese-owned Kokuka Courageous, was carrying methanol, a highly volatile liquid used produce biodiesel.

On Friday, President Donald Trump claimed to Fox News, “Iran did do it and you know they did it because you saw the boat.”

On Friday, the Pentagon released photos and footage it claimed showed a boat belonging to Iran’s Revolutionary Guard, a force designated as a terrorist organization by the Trump administration, removing what they said could be a mine from the side of one of the ships.

While the U.K.’s Foreign Secretary Jeremy Hunt, whom Trump praised on a recent visit, said there was “no reason not to believe the American assessment,” Germany has said that the video does not provide adequate proof of Iran’s involvement with the attack. Other nations, including France and China are urging calm and restraint in the region.

U.N. Secretary General Antonio Guterres is also pushing for an independent probe of the incident.

Iran denies having anything to do with the attacks, and the operator of the Kokuka Courageous told the press on Friday that their ships were not attacked by mines or torpedos, as the damage is to the vessel was above the water line. In fact, the crew of the ship said their vessel was hit by some kind of flying projectile

Malcolm Nance, U.S. intelligence expert who served in the navy for 20 years, participating in counter-terrorism, intelligence, and combat operations, including against the Iranians in the Persian Gulf, told ThinkProgress that it looked like the United States was trying to build a case for war.

“What I’m seeing is people that want to talk themselves into action, and when you do that, every bit of intelligence looks like hard intelligence. We saw that in the run up to the invasion of Iraq,” said Nance.

Considering what the Pentagon has provided — grainy photos and video from hours after the indecent — Nance said the evidence isn’t enough to incriminate Iran at this stage, unless the United States had come to that conclusion from the start.

“The photos that we’ve seen from the USS Bainbridge? Correct. The video that we saw from the aircraft? That’s correct. But when you lay that out in the timeline, and come into the game saying, ‘We’re going to find Iran doing something,’ well… everything is going to look like trouble,” Nance said.

The video, he added, “does not show an attack.” What it might be showing us, in fact, is the Iranian Navy being cautious.

“The evidence that they showed is a response, six to 10 hours after the attack. To remove explosives off the side of a vessel that is full of oil, that’s prudent,” said Nance.

Secretary of State Mike Pomepo, who held a press briefing on Thursday, has defended the U.S. assessment that Iran was responsible, “based on intelligence, the weapons used … and the fact that no proxy group operating in the area has the resources and proficiency to act with such a sophistication.”

He also accused Iran of striking the ships in order to “insult” Japanese Prime Minister Shinzo Abe, who was in Iran on a visit at the time.

Abe was speaking to Iranian officials about ways to cool tensions between Iran and the United States after President Donald Trump pulled out of the 2015 nuclear deal, reimposed sanctions, threatened others dealing with Iran with secondary sanctions, and sent a war ship and bombers to the region.

Trump has said he’s willing to negotiate with Iran, but Iran has indicated fresh talks are out of the question until he lifts sanctions that have hit the country’s economy hard, especially the oil sector.

Both Trump and Pompeo point to Iran’s threats to close the Strait of Hormuz, through which approximately 15% of the world’s oil supply is transported, as proof that Iran was behind the tanker attacks.

This seems unlikely, given that Iran is trying to convince its trading partners to continue to buy its oil. Given those suspicions, and the photos and videos presented as proof, which Nance said are “not definitive,” the administration’s narrative seems questionable at best.

“Either they have intelligence they’re not sharing or have misinterpreted what little they’ve seen,” said Nance.

Logistically, it takes a lot to get a mine onto a ship like the Front Altair or the Kokuka Courageous. First, a ship would have to run up the side of these boats, stick with them, use a gaff or hook to stick a magnetic mine on the boat, then sail off without being detected.

“There are watches on these ships who are looking around for objects so they don’t run into other ships,” said Nance. “So how are you going to miss that?”

Thursday’s incident is the second one involving a sabotage or attack of ships in the region. In May, ships belonging to Saudi Arabia, U.A.E. and Norway were also the targets of an attack.

The United States also immediately blamed Iran for that incident, although no evidence has been presented that would prove that Iranian forces or proxies were responsible.

On June 7, investigators turned in evidence to the U.N. Security Council on that incident, which pointed to an unnamed “state actor” being responsible for the attack.