Trump's foreign policy dilemma laid bare by Iran tensions

US President Donald Trump delivered his latest ultimatum to Iran on Thursday during a meeting of the Board of Peace, the Middle East coalition Trump formed to stabilise a region he could soon plunge into a new war.

The irony of simultaneously calling for peace and threatening military action underscored the competing impulses at the heart of Trump's foreign policy in his second term.

Perhaps nowhere is that contradiction clearer than the impasse between Washington and Tehran - a standoff that has quickly escalated and could now lead to the largest US air campaign in years.