By Edward Wong, New York Times–

In repeating his readiness to pursue a new nuclear deal with Iran, President Trump this week left unmentioned his administration’s aim to hobble what officials call Tehran’s “expansionist foreign policy” — an ambitious priority that is far more likely to lead the United States into war.

The expansive, open-ended mission of wrestling with Iran’s diplomacy and military activity could prompt armed conflict well before any showdown over a nuclear program, according to lawmakers, former government officials and analysts.

The rising tensions between the United States and Iran this month have been fueled by American suspicions of Iranian military activity. And there is no sign that Iranian leaders, who proudly regard their nation as a major international player and a successor of Persian empires, will curb their attempts to exert influence across the Middle East.

On Wednesday, John R. Bolton, the White House national security adviserasserted without presenting evidence that naval mines “almost certainly from Iran” caused recent explosions at four oil tankers in the Persian Gulf.

Iranian officials said the accusation was “ridiculous,” and Ayatollah Ali Khamenei, the country’s leader, announced that his government would not negotiate with the United States. Even in talks with Europeans or others, he said, certain issues were off limits: “We won’t negotiate our military capability.”

Mr. Bolton and Secretary of State Mike Pompeo, both anti-Iran hawks, have forcefully and increasingly pushed for countering Tehran’s foreign policy since last year. Iran’s spreading influence — supporting Arab militias and political parties that include Hezbollah in Lebanon, the Houthi rebels in Yemen and a constellation of Shiite groups in Iraq — has also infuriated Israel and Saudi Arabia, both key American allies in the region.

“We could get into a shooting war with Iran,” said Representative Ruben Gallego, Democrat of Arizona and a former Marine who served in Iraq. “That’s the danger over what Bolton is doing and what the administration is doing right now.”

Mr. Gallego, who sits on the House Armed Services Committee, said he had been briefed on intelligence on Iran. He said Trump administration officials were “hearing what they want to hear, and they’re being fed what they want to be fed, in order to push us closer to war.”

By contrast, it could take many months for Iran to come within one year of making enough fissile material for a weapon — even if it aspires to that.

“It’s not just about a nuclear weapon, as you know,” said Morgan Ortagus, the State Department spokeswoman. “It’s about Iran’s support of terrorism in the region, their malign behavior throughout the region.”

The relentless focus on Iran’s growing reach has led to clashes within the Trump administration; military and intelligence officials have said the Islamic State and Al Qaeda present much greater threats to the United States and its interests.

Some analysts described the anti-Iran language used by Mr. Bolton and Mr. Pompeo as belligerent, alarmist and, in fact, paradoxical. The president’s two top foreign policy advisers assert that Iran’s government has been thoroughly weakened by sanctions, even while they accuse Tehran of being the most powerful bad actor in the Middle East.

“Iran has been subject to U.S. sanctions and containment for four decades,” said Ali Vaez, an Iran expert at the International Crisis Group. “Yet U.S. officials believe that Iran’s clout has threateningly grown over the same period of time. Maybe it’s time for Washington to rethink its policy toward Tehran rather than doubling down on the failed policies of the past.”

Mr. Trump himself has never expressed any strong desire to contain Iran on all fronts, as Mr. Bolton and Mr. Pompeo have.

Last Friday, Mr. Trump announced he was sending 1,500 additional American troops to the Middle East. But it was a reluctant order, and the number was much smaller than what Iranian hard-liners in the administration had requested. As a presidential candidate, Mr. Trump called for an isolationist foreign policy and avoiding a Middle East quagmire.

The administration’s expansive policy against Iran came into sharp focus — and into conflict with Mr. Trump’s instincts — last fall.

At that point, Mr. Bolton and James F. Jeffrey, the State Department’s special representative for Syria, began asserting that the United States would not leave Syria until all Iranian forces had departed. Iran, like Russia, has been a main ally of President Bashar al-Assad in the eight-year Syrian civil war.

At the height of the war against the Islamic State, American and Iranian forces in Syria and Iraq worked in parallel — though never together — against the Sunni Muslim extremist group. In December, Mr. Trump declared victory over the Islamic State and announced he was withdrawing troops from Syria. He has since agreed to leave some troops there, and only once mentioned a desire for the American military to “watch Iran” from Iraq.

Mr. Bolton and Mr. Pompeo, on the other hand, have persisted in a policy of subduing Iran as broadly as possible — and setting the conditions by which the American military might confront Iranian forces or their partnered Shiite Arab militias.

On May 5, after the Pentagon received intelligence of what officials called a potential threat by Iran or its allied militias, Mr. Bolton announced the accelerated movement of an aircraft carrier and bombers to the Persian Gulf region. He said “any attack on United States interests or on those of our allies will be met with unrelenting force.”

Critics said that if there was a heightened threat, the Trump administration had provoked Iran by withdrawing from the 2015 nuclear deal, reimposing harsh sanctions and designating an arm of the Iranian military as a terrorist organization.

Former American officials say that from 2011, when the American military departed Iraq, to 2018, when Mr. Trump left the nuclear deal, there were no attacks directed by Iran against American interests, which showed that diplomacy led by President Barack Obama had worked.

Mr. Bolton’s broad warning means the United States could take military action against Iran over tangential episodes — like a drone operated by Houthi rebels attacking a Saudi oil pipeline or airport, or an Iraqi armed group firing a rocket toward the Green Zone in Baghdad.

Likewise, in announcing new economic sanctions targeting Tehran, American officials have stressed the need to curb Iran’s foreign policy.

“With this decision today, we expect to see more positive impacts to deny Iran the revenue it needs to conduct its foreign policy, to fund its proxies and satellites around the region, to fund its missile program,” Brian Hook, special representative for Iran, said on April 22 after the Trump administration announced it was ending permission for eight countries to buy Iranian oil.

But if the general aim is to counter Iranian policy, the Trump administration appears to be giving up its diplomatic tools in Iraq, a critical battleground for influence. Iran has planted deep roots there since 2003, when President George W. Bush toppled the government of Saddam Hussein, an enemy of Tehran.

On May 15, Mr. Pompeo ordered the withdrawal of almost all diplomats from the United States Embassy in Baghdad based on a threat assessment related to Iran. Last September, he closed the American Consulate in Basra.

The State Department also updated a travel warning for Iraq, prompting Exxon Mobil and other American companies to withdraw workers from projects that are partly aimed at helping Baghdad wean itself off dependence on Iranian energy.

The moves upset Iraqi leaders, who welcome American engagement to help balance against Iran. They and former American officials note that even when the Islamic State took over large swaths of Iraq in 2014, the United States did not order a diplomatic withdrawal.

“It’s a government that wants us present,” said Brett McGurk, the former special envoy to the coalition fighting the Islamic State. “If you abandon the field diplomatically, you needlessly cede to Iran.”