President Donald Trump's administration on Tuesday appeared set on easing weeks of escalating tensions with Iran, assuring worried lawmakers it does not seek war and crediting robust US military moves with deterring the clerical regime.
After a month of fiery warnings to Iran, top Trump officials delivered a classified briefing to the full US Congress where Democrats have accused the administration of hyping intelligence and pushing the United States dangerously close to war.
"This is about deterrence, not about war. We are not about going to war," Patrick Shanahan, the acting defense secretary, told reporters after exiting the closed-door briefing he gave with Secretary of State Mike Pompeo.
Shanahan cast the US deployment of an aircraft carrier strike group and nuclear-capable B-52 bombers as reactive actions -- and said they sent a strong signal.
"We have deterred attacks based on reposturing of assets -- deterred attacks against American forces," Shanahan said.
"Our biggest focus at this point is to prevent Iranian miscalculation. We do not want the situation to escalate," he said.
Pompeo and Shanahan are believed to have shared intelligence that blamed Tehran -- enemy number one for Trump -- for security incidents involving US-allied Arabs.
Pompeo, in an interview earlier Tuesday, said it was "quite possible" Iran was behind sabotage of oil tankers off the United Arab Emirates as well as drone strikes on a crude pipeline in Saudi Arabia, although he stopped short of giving a definitive conclusion.
Yemen's Huthi rebels, who are allied with Iran and are being hit hard by US-backed Saudi air strikes, claimed responsibility last week for a drone strike on a major east-west pipeline in the kingdom, which was forced to shut down temporarily.
Representative Michael McCaul, the top Republican on the House Foreign Affairs Committee, said the administration made a convincing case that Iran and its proxies were behind numerous attacks -- including a rocket that landed Sunday near the US embassy in Baghdad, which has been evacuated.
But McCaul also cast the US response as deterrence, telling reporters: "It was made very clear... there is no intention to go to war."
- 'Very dangerous game' -
Iranian Foreign Minister Mohammad Javad Zarif warned that the United States was "playing a very, very dangerous game" with military deployments, saying that some actors were "interested in accidents" -- a likely allusion to its regional rivals such as Saudi Arabia.
"There will be painful consequences for everybody (if) there is an escalation against Iran, that's for sure," he said," Zarif told CNN.
Trump last year pulled out of a multinational agreement negotiated under his predecessor Barack Obama under which Tehran drastically scaled back its nuclear work in return for promises of sanctions relief.
The administration, which is closely allied with Riyadh, instead vowed "maximum pressure" to weaken Iran's regional influence, including by trying to stop all oil sales by Tehran.
Democrats, while criticizing Iran, said its actions were predicted responses to Trump's actions and vowed to hold the White House to account after the debacle over the 2003 invasion of Iraq.
Senator Bernie Sanders, an independent leftist who is seeking the Democratic presidential nomination, said that both the Iraq and Vietnam wars were based on lies.
"I worry very much that, intentionally or unintentionally, we can create a situation in which a war will take place," Sanders told reporters.
"I believe that a war with Iran would be an absolute disaster, far worse than the war with Iraq," Sanders said.
Representative Adam Smith, a Democrat who leads the House Armed Services Committee, said that Pompeo in the briefing gave "a very lengthy political argument" explaining "all the terrible things Iran has done" until the Democratic lawmaker said he cut him off and asked to hear about US policy.
"I think there's a risk of miscalculation on both sides. And that remains my biggest concern," Smith said.
- Opening on prisoners? -
Numerous Republicans have been clamoring for a tough stance on Iran that includes military options.
Senator Lindsey Graham, a longtime hawk who is close to Trump, called the classified briefing a "game-changer."
"The appeasement strategy against Iran is over," he declared after the briefing.
But Trump has sent mixed signals, on Sunday warning by tweet that the United States could obliterate Iran while also calling for talks.
He similarly threatened North Korea before his historic meetings with its leader Kim Jong Un, although few expect Iran's leadership -- for whom anti-Americanism is a cardinal tenet of the 1979 Islamic revolution -- to meet Trump.
But Zarif has proposed a swap of prisoners, a step some observers say could offer a path to resume at least low-level dialogue to ease tensions.
Pompeo, in a radio interview with conservative host Hugh Hewitt, said without further explanation that there had been "just a hint" that Iran was moving to release imprisoned US citizens.
"Even a small confidence-building measure is a good thing, so it's absolutely the case that were they to release these Americans who are wrongfully held, it would be a good thing," Pompeo said.