PARIS — President Trump and his aides have sent a dizzying, seemingly conflicting set of messages to Iran in recent weeks, ordering more troops to the Middle East and a carrier to the Arabian Sea as military threats even while declaring that Washington is seeking new negotiations, not war.
European allies, still trying to save a 2015 deal to restrain Iran’s nuclear program that Mr. Trump abandoned a year ago, are trying to make sense of the administration’s strategy.
And the government in Tehran, humiliated by Mr. Trump’s hard-line policies, has all but frozen diplomacy with Washington. “Standing and resisting the enemy’s excessive demands and bullying is the only way to stop him,” Iran’s supreme leader, Ayatollah Ali Khamenei, said on Tuesday.
Yet it appears Mr. Trump wants to play the role of neither conqueror nor courtier, walking a fine line between military threats and diplomatic outreach but committing to neither. At various points, he has warned that there is “always a chance” of conflict with Iran while urging negotiations — with no visible plan to make them happen.
On Thursday, Mr. Trump and President Emmanuel Macron of France sought to paper over their sharp differences on how to deal with Iran by focusing on their shared goal of preventing Tehran from obtaining a nuclear weapon. Mr. Macron has said the best way was the 2015 agreement.
“I understand they want to talk,” Mr. Trump said of Iran’s leaders during a news conference with Mr. Macron in France. “And if they want to talk, that’s fine. We’ll talk.”
Mr. Macron called his words “very important.”
“We need to open a new negotiation,” Mr. Macron said.
Mr. Trump has made similar comments since the White House escalated tensions with Iran last month. But his administration has not outlined specific goals for the negotiations, nor offered Tehran any incentives to begin talks.
Some American officials fear the president may have undercut his own leverage by repeating that he does not want a conflict with Iran — deliberate or accidental — as the 2020 election approaches. And Mr. Trump has recently distanced himself from the White House national security adviser, John R. Bolton, who publicly advocated regime change for years before joining the administration.
But Mr. Trump has also shown little interest in setting up a real diplomatic process to begin talks with Iranian leaders, the officials said, including resisting the kind of secret, back-channel discussions that President Barack Obama started several years before broad negotiations began.
In short, Mr. Trump neither avidly supports engaging Iran nor wants to be so confrontational to provoke Tehran into lashing out. Administration officials insist this middling course has worked — at least so far.
Several senior Defense Department officials have pointed to the public decision to accelerate the movement of bombers and the Abraham Lincoln, a Nimitz-class carrier, outside the Persian Gulf, as the reason Arab militias tied to Iran have refrained from attacking American interests, including in Iraq. But even if that was an effective deterrent, the officials said, it was not a long-term strategy.
As with so much about Mr. Trump, his diplomatic overtures to Iran amount to little more than performance.
As one British diplomat said while Mr. Trump was arriving this week in London for a lavish state visit, there was “no visible plan” to entice Iran’s leaders into a more permanent cessation of its nuclear activity.
A French official said Mr. Trump’s action may have reinforced the Iranian leaders’ conviction that they will always need a pathway to a bomb.
In the past year, Mr. Trump has followed the advice of Mr. Bolton and Secretary of State Mike Pompeo by trying to punish Tehran as thoroughly as possible — first by withdrawing from the 2015 nuclear deal that he often described as a “terrible agreement” because it did not put a permanent lock on Iran’s production of nuclear fuel.
Then Mr. Trump began reimposing harsh sanctions — even though Europe, China and Russia, which participated in the original nuclear negotiations, said they wanted to continue trading with Iran.
The reaction from Iran has been cautious.
Over the past year, Tehran has remained inside the constraints of the deal, largely to stay aligned with Europe. But last month, President Hassan Rouhani, under pressure at home, set a schedule for beginning to walk back from some of Iran’s earlier commitments, making clear that if Mr. Trump continued to step up sanctions pressure, his country would begin producing nuclear fuel.
So far, the only direct response to Mr. Rouhani has been a warning from Mr. Pompeo that the United States would not let Iran get within a year of being able to produce enough fuel for a single bomb — the same standard that was set under Mr. Obama.
But American officials said the new offer to negotiate is intended to signal that the administration does not outright reject the idea of a deal with Iran, just not the one struck by Mr. Obama.
The officials said the approach, combined with threats of military action, aims to prevent Tehran from getting back into the nuclear fuel business, attacking American interests and prompting an escalatory cycle of violence. Mr. Trump’s equivocal posture toward Iran, however, has raised doubts that the strategy would keep hard-liners in Tehran from taking more aggressive, or even violent, measures against the Americans.
That has added to the uncertainty over an expansive, open-ended campaign by Mr. Trump and his administration that focuses as much on confronting Iran’s entire foreign policy as on the more limited goal of preventing the building of nuclear weapons.
“The problem is he believes that maximum pressures and threats are a negotiating strategy,” said Ali Vaez, the Iran project director at the International Crisis Group. “But both are anathema in the Iranian culture.”
On Tuesday in London, Mr. Trump and Theresa May, the outgoing British prime minister, said they had discussed Iran and remained committed to preventing it from developing a nuclear weapon. But they said they differed on the means because Britain has remained in the 2015 nuclear deal and wants Iran to do so, too.
Tensions between the United States and Iran soared in May after Mr. Bolton announced the administration was ordering the aircraft carrier strike group and bombers to the Middle East. American officials said new intelligence indicated a heightened threat from Iran or its allied militias that followed tighter oil sanctions imposed by the United States and the designation of an arm of the Iranian military as a terrorist group.
Though European allies and Democrats in Congress raised doubts about the threat level, Mr. Trump announced on May 24 that he would deploy an additional 1,500 troops to the Middle East. However, officials said he did so only reluctantly, and his vow to use military force has largely lacked weight, especially after comments in which he said he sometimes restrains Mr. Bolton.
Mr. Trump’s assertions that he is ready to negotiate sound hollow, too.
Questions about whether Mr. Pompeo was trying to secretly start a back channel to Iran dogged him on this three-night trip last week to Switzerland, a traditional interlocutor between Washington and Tehran. In the end, the speculation appeared overblown.
On Sunday, at a news conference in Bellinzano, Mr. Pompeo said he was ready to talk to Iranian officials with “no preconditions,” showing potential openness to recalibrating 12 demands he has made of Iran.
But standing beside Mr. Pompeo, Ignazio Cassis, the foreign minister of Switzerland, said neither the United States nor Iran had asked the Swiss to help with new negotiations.
“Both parties are now increasing the pressure, and for the rest, this is a matter of worry,” Mr. Cassis said, “but we cannot do anything unless we get a mandate from both parties.”
Like Mr. Trump, Iranian leaders have expressed little enthusiasm about the prospects of negotiations. The country’s foreign minister, Mohammad Javad Zarif, has said repeatedly that before Iran would open any negotiations, the United States would have to return to the 2015 deal — a step Mr. Trump has rejected.
On Saturday, Mr. Rouhani said that Iran could talk again, but not under coercion: “We have shown that we do not submit to bullying.”