Just how powerful is Global Britain, as the country walks out of the EU door? The question has taken on a certain urgency given the disturbing events of the last few days regarding Iran.

Mohsen Fakhrizadeh, the country’s most senior nuclear scientist, was assassinated on the outskirts of Tehran on Friday. The Iranians immediately blamed Israel, which is not as outrageous a claim as some the Islamic Republic makes. Tel Aviv has made no secret of its wish to curb Iran’s nuclear ambitions – as it did earlier with Iraq – and Dr Fakhrizadeh was not the first leading Iranian scientist to be “taken out”. Israeli Prime Minister, Binyamin Netanyahu, has at times made graphic presentations about what he sees as the Iranian nuclear threat.

Disturbingly, reactions in the Iranian media over the weekend included the suggestion that Haifa should be targeted for reprisals – even though would mean civilian casualties. The security situation for the whole region has suddenly got a whole lot worse.

This has not been helped by the posturing of the Trump administration in Washington. It may be in its dying days but both President Trump and Secretary of State Mike Pompeo seem determined to keep the embers burning long enough to take a hefty swipe at Iran. US military aircraft have increased their presence in the Gulf and there have been repeated “rumours” that the White House is planning to hit Iran hard over the next few weeks. That would be taking Pompeo’s strategy of “maximum pressure” on Iran up to a whole new, potentially catastrophic level.

So where is Britain in all this? Foreign Secretary Dominic Raab made a principled but rather weak call for calm in the wake of the Fakhrizadeh assassination. But was anyone listening? As a UN Security Council member, the UK should nonetheless still have an important voice on such matters. But of course, it has plenty of history with Iran – not all of it positive.

The Iranians often refer to Britain as the “old cunning fox”, remembering both how the Anglo-Iranian Oil Company screwed their country out of its natural resources and how Britain backed a coup against Prime Minister Mohammad Mossadegh when he tried to put a stop to that. That should not prevent London stepping up to the plate as the tension grows, however.

Britain is a self-declared friend of both Washington and Tel Aviv. Whoever really was behind the latest killing it is important that the voice of reason be heard loud and clear. That includes standing firm on getting the JCPOA Iran nuclear deal back in force, as President-elect Joe Biden has indicated he will.

An attack on either Iran or Israel meanwhile could enflame the whole of the Middle East region. In this regard, let us pray meanwhile that the Trump administration decides to go out not with a bang but with a whimper.

* Jonathan Fryer is Chair of the Federal International Relations Committee.