In Trump's shadow, Vance becomes face of Iran deal

But there is no guarantee the two sides will broker a final deal on various deeply technical issues over the next 60 days, or that a long-term agreement would satisfy critics at home and abroad.

"Vance being connected to the Iran war is one more way [that critics will] hold him accountable for Trumpism," said Terry Holt, a veteran Republican consultant.

The week of mixed messages on this deal illustrated Vance's challenge on Iran.

The administration announced that Iran had agreed to the memorandum of understanding on Sunday, but did not release details.

The lack of clarity sparked confusion about what was actually in the text of the deal. Vance then tried to clear up the confusion in several interviews.

He told CBS News on Monday that Iran "could have access" to a $300bn reconstruction fund if it abided by the terms of its deal with the US.

Hours later, Trump said in a social media post that reports of the US paying Iran as part of the $300bn fund were "Fake News" and told reporters "we're not putting up 10 cents".

When the text of the agreement was finally released by US officials, it included a provision committing the US to work "with regional partners to develop a definitive mutually agreed plan with at least USD $300 billion" for Iran's reconstruction.

On Iran's nuclear programme, Vance echoed Trump's assertion that the interim agreement was a significant first step toward stopping Iran from developing nuclear weapons.

But the deal did not address the nuclear question in detail, leaving that to be settled in the next round of talks.

Throughout the week, Vance was also promoting his new book about his faith and conversion to Catholicism.

But even in those media appearances he could not escape the news of the day.

As he was sparring with Whoopi Goldberg on ABC's The View, Trump was meeting with world leaders at the G7 summit in the French resort town of Évian-les-Bains.

At his press conference on Wednesday, Trump reprised the joke he has made in recent months that he would blame Vance if the Iran deal fails.

Trump also appeared to downplay the significance of the memorandum of understanding, at one point questioning whether it was an important enough document for him to sign.

Then, soon afterwards, Trump signed a paper copy of the deal on camera during a lavish dinner with French President Emmaneul Macron at the Palace of Versailles - raising questions about why Vance would then need to stage a separate signing event of his own in Geneva.

A question that was answered later when the White House announced Vance would not be travelling there - at least for now as logistics for talks with Iran were not yet finalised.

With Trump still out of the country, Vance had continued defending the deal as his former colleagues in the Senate criticised it for giving up too much to Iran.

"Iran's nuclear ambitions were not curbed, and they have learned that threatening the Strait of Hormuz works and will undoubtedly leverage it in the future," Republican Senator Bill Cassidy of Louisiana said in a post on X.

Senate Armed Services chairman Roger Wicker of Mississippi said on Thursday that the deal was "completely out of step with the president's goals".

Vance pointed to falling petrol prices at the press briefing on Thursday, arguing that the deal was already paying dividends to Americans.

He expressed confidence that it would continue to bear fruit so long as Iran made good on its promises and agreed to a final peace deal once the key issues have been negotiated.

"If they change their behaviour, big things are going to happen," Vance said. "If they don't, no skin off our backs. Either way, we win."

With Vance leading these negotiations, as Trump made clear, he will have a lot riding on a victory - or a defeat.