No tougher agreement will follow it; America will be in the wrong and at odds with its friends in Europe

LAST summer John Bolton was a hawk with clipped wings. The former ambassador to the UN and cheerleader for the Iraq invasion was grumbling that White House staff were thwarting his attempts to give President Donald Trump his plan for scrapping the Iran nuclear deal brokered by Barack Obama in 2015. Not any more. On April 9th Mr Bolton, whose walrus moustache and verbal bluster mask a skilled and ruthless bureaucratic infighter, becomes Mr Trump’s national security adviser. As a result, that deal to roll back Iran’s nuclear-weapons programme seems on its last legs. That is bad news for the Middle East, for America’s allies and for America itself.

Mr Trump has long scorned the deal, the Joint Comprehensive Plan of Action (JCPOA), as the “worst ever”. Yet every 120 days he must sign a waiver for sanctions to remain unenforced—and hence for America to continue to honour the agreement. Mr Trump half-disowned the Iran pact in January, but the sobersides in uniforms and suits running his foreign policy at the time persuaded him to give its European parties, Britain, France and Germany, one last chance to fix it.

The Europeans could point to reports from the International Atomic Energy Agency that Iran is sticking to the letter of the deal (which was also signed by Russia and China). They can envisage side-agreements to penalise Iran for its pursuit of ballistic missiles and to demand easier access to military sites for nuclear inspectors. They are willing to tackle the sunset clauses allowing, for example, curbs on uranium enrichment to lapse over time. But they have no appetite and see no legal case for reneging on a hard-won agreement. The best they can imagine is a declaration saying that the JCPOA’s signatories will demand that a renewed Iranian nuclear programme is unambiguously peaceful. That falls far short of American demands (see article).

Ever the cynic, Mr Trump accuses British and French leaders of liking the Iran deal because their countries make money trading with Iran. His new advisers share his bleak worldview. Rex Tillerson, sacked as secretary of state on March 13th, is being replaced by Mike Pompeo, also a fierce critic of the accord. As for Mr Bolton, he has asserted that only military force can slow Iran’s sprint towards a lethal nuclear arsenal.

Although he has recently sounded less hawkish, his hiring surely dooms the Iran deal. But if Mr Trump does ditch it, he will find that his aides and allies were right: nothing better will replace it. The chances of Iran agreeing to tighter constraints are minimal. The hardest-line Iranian factions will pour scorn on colleagues willing to give diplomacy a try yet again.

When worst comes to worse

The damage to America’s reputation will extend far beyond the Middle East. Why would North Korea agree to swap its nuclear bombs for an accord that a future American president could simply rip up? The transatlantic alliance would face unprecedented strains. Europe would find itself siding with China, Russia and Iran against America. New American sanctions might try to force European companies to choose American over Iranian markets. European governments might feel compelled to support their defiance.

And, on top of all that, Iran might resile from the deal, further roiling an unstable region at risk of tit-for-tat nuclear proliferation. That would leave America nothing to fall back on but bombing Iran’s nuclear sites (every few years, because air strikes cannot destroy know-how). With an arch-hawk like Mr Bolton at Mr Trump’s side, expect much rhetoric about America seeking peace through strength. Yet ditching the Iran deal risks war, and is more likely to make America weaker.