Analysis: With defence secretary’s firing and potential new Iran sanctions, Trump raises fears over impact of a vengeful president

The abrupt dismissal of the US defence secretary, Mark Esper, and reported plans for multiple layers of new sanctions on Iran have made clear that Donald Trump’s last 10 weeks in office could still prove a very bumpy ride for the rest of the world.

Trump is refusing to concede his loss to Joe Biden and, while he launches a quiver of baseless legal challenges to the results, he is also seeking to demonstrate he is still in charge of foreign and defence policy – fueling fears about the impact a vengeful president might have on the US role on the world stage over the coming 10 weeks