The Trump administration took the USA out of President Obama's nuclear deal with Iran.
The US withdrawal was backed by Israel, Saudi Arabia and other Arab states but opposed by the EU, the UK, and the BBC's Middle East editor Jeremy Bowen.
Here's the latter, on today's From Our Own Correspondent, expressing his view on the matter again:
Donald Trump had an even bigger impact on policy towards Iran. The Obama administration, along with other permanent members of the UN Security Council and Germany, stopped what I believed was a steady slide to war by making an agreement with Iran about its nuclear activities. It wasn't perfect deal - show me one that is - but it was a chance for a new beginning.
His FOOC piece was also notable for focusing on what matters to Jeremy Bowen - the Palestinians - while missing out the remarkable peace deals between Israel and Arab countries. And President Trump's dogged reluctance to entangle the US in Middle Eastern wars, unlike all his recent predecessors (also unmentioned), adds an ironic twist to his concluding advice (prayer?) for Joe Biden: "Perhaps the most constructive move Joe Biden can make after his inauguration is to concentrate more on diplomacy, less on drones and the other dogs of war."