The Biden administration had warned that the United States would consider any Iranian attempt on Mr. Trump’s life to be “an act of war,” officials said.

Is Iran so scared of Donald Trump that it’s starting (or pretending) to play nice? That’s the question on the minds of U.S. national security officials and analysts as Tehran braces for another four years of Trump.

The last time Donald Trump was US president it spelled disaster for Iran — he walked away from a landmark nuclear deal, derailed the country’s economy with sanctions and killed its most revered general.

The Iranian message was a response to a warning from the US in September, which made it clear that threats against Donald Trump are a critical national security concern and any attack on him would be treated as an act of war.