In the middle of an Easter lunch at the White House, President Donald Trump went off script to address speculation about JD Vance's role in securing a deal to end the war in Iran.

"If it doesn't happen, I'm blaming JD Vance," Trump joked, drawing laughter at last week's East Room event attended by senior administration officials including the vice-president, Secretary of State Marco Rubio, and Defence Secretary Pete Hegseth. And "if it does happen," Trump added, "I'm taking full credit."

The remarks perfectly captured Vance's predicament as he leads a US delegation holding talks with Iran in Pakistan. It is the most challenging assignment of Vance's vice-presidency so far - one with a limited upside and plenty to lose if negotiations fail.

Vance's diplomatic mission to Islamabad is a political minefield. To make progress in reaching a permanent agreement to end the war, he will have to satisfy several stakeholders with competing interests, and who all distrust each other after a six-week military campaign that has engulfed the Middle East and roiled the global economy.

US allies are watching Vance closely to see how he'll perform, one European official said. Vance "needs to step into the room and deliver something," added the official, who spoke on the condition of anonymity. "Otherwise he will be diminished."

Any deal must win the support first and foremost of Trump, who has vacillated between calling for peace and threatening to destroy Iran's civilisation. It will also need the backing of a weakened but still-standing regime in Tehran that has tightened control over the Strait of Hormuz, and an ally in Israel that is wary of a region-wide ceasefire. US allies in Europe that oppose the war and have been reluctant to come to America's aid in reopening the strait will also have to be convinced.

As if that's not enough, Vance will also face pressure to somehow satisfy Trump's Make America Great Again (MAGA) base. Many are opposed to interventions abroad so will be watching his trip closely for clues about how he might handle foreign policy if he runs for president in 2028.

A former Marine who served in Iraq, Vance has been a vocal opponent of US entanglements in the past, and reportedly expressed deep scepticism about launching strikes on Iran in private meetings with Trump, according to a New York Times report.

"Vance has signalled a desire for restraint in American foreign policy. That's pretty hard to square with the American war against Iran," said Jeff Rathke, the president of the American-German Institute, a Washington-based think tank.

Satisfying a demanding boss

In Islamabad the question for Vance is: can he make everyone happy? And what does success in these negotiations look like - a fully-formed peace deal, or just productive initial talks that don't scuttle the temporary ceasefire?

A White House official told the BBC that Trump had tasked the vice-president to lead the negotiations. And spokeswoman Anna Kelly confirmed that Vance had already been collaborating with special envoy Steve Witkoff and the president's son-in-law Jared Kushner, both of whom will be with him in Pakistan.

Vance tamped down expectations before leaving Washington on Friday morning.

"If the Iranians are willing to negotiate in good faith, we are certainly willing to extend an open hand," Vance told reporters. He also warned Iran not to "play us," and said Trump gave the US negotiating team "some pretty clear guidelines".

But even if he laid out clear goalposts ahead of time, the president has a propensity to change his mind. In the talks with Iran, Vance and the rest of the US team will face the added challenge of representing a mercurial boss in Trump who has given a range of rationales for the war since launching the conflict in late February.

On Friday afternoon, when asked what he told Vance before he left for Islamabad, Trump told reporters: "I wish him luck. He's got a big thing." The president said he was sending a "good team" and "we'll see how it all turns out."

Trump's volatile negotiating style was on full display this week, in the whirlwind period leading up to the ceasefire deal reached on Tuesday. In a single 36-hour span, Trump gave Iran one day to strike a deal, warned in social media posts on Truth Social that "a whole civilisation will die" if Iran refused to cooperate, and then finally announced a ceasefire with less than two hours left before his deadline for escalating the war.

The tense hours on Tuesday were as nervewracking as any moments in Trump's second term, said a second senior European diplomat.

"I went home from work, put on the news, and started refreshing Truth Social," said the official, who spoke on the condition of anonymity. Serving as Trump's vice-president can't be easy under normal conditions, the diplomat added, but must be especially difficult for Vance right now given his misgivings about foreign wars.

"Vance has tried to distance himself from the Iran campaign," the source said. "This war is absolutely not in his playbook."

Ambassador for 'America First'

Representing Trump in high-stakes negotiations may be a challenge, but Vance has been working toward this moment since taking office. He has earned Trump's trust and been given a seat at the table in high-profile meetings and events with foreign policy leaders in the Oval Office and across Europe and Asia.

Vance made waves with a speech at the Munich Security Conference last year, where he issued a blistering critique of Europe's handling of immigration and free speech. Soon after, he accused Ukrainian President Volodymyr Zelensky of not being grateful enough for US aid during an explosive Oval Office meeting that descended into a shouting match. Just this week, the vice-president travelled to Hungary to make an unprecedented re-election push for the current prime minister and close Trump ally Viktor Orbán.

At each step, Vance has positioned himself as a loyal lieutenant to Trump who's willing to crisscross the globe serving as a sharp-elbowed ambassador of "America First".

The vice-president is the "perfect surrogate" in these high-stakes negotiations because of "his firm understanding of President Trump's goals", said Mark Bednar, who worked on the Trump-Vance transition team. "To also have the trust of the president the way he does, that is a really great combination."

But Vance reportedly hasn't always agreed with the president. And Trump's own foreign policy has sometimes put Vance in the awkward position of publicly backing the type of interventions abroad that he has argued against in the past - Iran being the prime example.

As a US senator Vance published a Wall Street Journal op-ed in 2023 saying he backed Trump because he didn't start foreign wars. On the eve of the Iran war, Vance told the Washington Post that Trump wouldn't let the US get dragged into another so-called forever war in the Middle East.

During the current conflict, he has publicly echoed Trump's argument that war was needed to prevent Iran from developing nuclear weapons. But Vance has not been as vocal in backing the war effort as other administration officials, in particular Defence Secretary Hegseth. Vance's rhetoric has also sometimes diverged from Trump's, as happened this week when Vance called the temporary ceasefire a "fragile truce".

Despite this, Trump tapped Vance to lead the US delegation to Islamabad. The choice raised questions of whether Trump purposely handed Vance a no-win assignment. The vice-president's office declined to comment for this story, but a US official who asked not to be named said Vance was chosen to send Iran a signal that the Trump administration was serious about reaching a deal.

No easy fix

US allies in the region welcomed Vance's inclusion on the team as a sign the administration wants a durable peace to end the war. "It shows that America is seriously coming to the table," said Assaf Orion, a retired Israeli brigadier general.

Vance will have to tune out the chatter back in Washington to deliver in negotiations with Iran.

The Oval Office confrontation with Zelensky and trips to Munich and Budapest all showcased Vance's ability to play the role of attack dog.

"If he feels the need to be argumentative, he's not going to shy away from that. If he feels that something is not going right for the United States, he will not shy away from that either," said Mark Bednar, the Republican strategist who's worked with Vance.

But in Pakistan he's playing a different diplomatic role, which will require navigating tense relations between adversaries in a volatile region. Vance and his team will also have to address a complex set of problems - including reopening the Strait of Hormuz and ending Iran's nuclear programme - that are highly technical and have no easy fix.

Vance was not involved at a detailed level in the indirect talks between the US and Iran before the ceasefire. Negotiations in recent weeks were led by Witkoff and Kushner, according to a US official. The pair also spearheaded other peace talks during Trump's second term. The success of the talks will rely in part on who handles technical aspects of Iran's nuclear programme, Orion said.

"Kushner and Witkoff did Ukraine, Iran and Gaza. I think it's very challenging to be a detailed expert in all three issues at the same time," Orion said. In Islamabad, "the question is who else, who is on the bench?"

Still Vance will command the most attention, regardless of whoever else is in the room.

The vice-president won't be able to rely on a deep well of personal relationships with foreign leaders built up over years. It can be easy to forget Vance is still just 41 years old, and only recently launched himself onto the national political stage when he ran for the US Senate. For all of his polish and shrewd instincts, he is still a relative newcomer to the world of international relations.

Nevertheless, Trump threw him into the deep end this week, and now Vance is under pressure to deliver a victory for the president while not damaging his own political future.

"He's not negotiating JD Vance's agreement with the Iranians. He's there in Islamabad to try to get the best deal the president can agree to," said Rathke. "But that has some risks for the vice-president, in case Trump agrees to something and then later loses his enthusiasm for it. Trump may try to blame the negotiator." (BBC)

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