America and Iran try to step back from the brink over nukes

FORthe past five years, since Donald Trump withdrew America from the 2015 nuclear pact with Iran, American presidents have sought a new bargain with their old foe. Mr Trump, then president, predicted that tough sanctions would compel Iran to sign a “new and lasting deal”. Joe Biden’s administration promised smart diplomacy to craft a “longer and stronger” agreement.Those efforts are sputtering towards an unsatisfying conclusion. Instead of making a deal, Iran has enriched more uranium to higher purity than ever before: it is on the threshold of being a nuclear-armed state. Desperate to halt its progress, America wants to negotiate a tacit understanding that would offer Iran a dollop of cash to freeze its nuclear work where it stands.