The choice Keir Starmer makes in the next 48 hours could define his premiership.
Tony Blair never escaped the accusation he had been George Bush’s “poodle” over the invasion of Iraq. And how far the current Labour PM goes in backing another US president in another foreign conflict could help or haunt him for years to come.
Sir Keir has urged Donald Trump to step back from the brink of a direct strike on Iran, warning against any action that would “ramp up the situation”.
The PM’s official spokesman said “de-escalation is the priority” after the US president threatened to wade into the conflict.
But, if that did happen, how could the UK respond?
One option – albeit the most diplomatically tricky – is to withhold support entirely.
Sir Keir has spent months trying to build a special relationship with President Trump. Anything less than support for their actions is likely to go down badly with the current White House regime.
However, the Attorney General Lord Hermer, a close political ally of Sir Keir, is reported to have raised legal concerns about any potential British involvement in the conflict beyond defending its allies.
Lord Hermer is reportedly reluctant to sign off any offensive operations, with a source telling The Spectator: “The AG has concerns about the UK playing any role in this except for defending our allies.”
The weight the Labour leader places on his old friend’s legal judgement could limit the extent of any support for the US, if Mr Trump does decide to act militarily. The PM’s own background will also play a role in the decision. The energy minister Miatta Fahnbulleh said on Thursday that he “who is a lawyer and a human rights lawyer, he will obviously do everything that is in accord with international law.”
But will he really risk infuriating President Trump at a time when the Republican’s tariffs on goods entering the US have already led economists to downgrade their forecasts for the UK economy?
Another option, considered the most likely, is to allow the use of the UK-US airbase at Diego Garcia in the Chagos Islands. The type of B-2 stealth bombers which are often based there are the ones that are capable of carrying specialised “bunker buster” bombs, which could be used against Iran’s underground nuclear facility at Fordo. This is a middle ground seen as the most likely option for the UK government to back. It would not require action from the UK, but could protect the relationship with the US by seeming to offer support.
He is already under pressure over the issue at home. Shadow foreign secretary Dame Priti Patel has said the UK should give permission for the US to use Diego Garcia to launch bunker-buster bombs.
One step beyond the Diego Garcia option is to provide logistical support to the US, and what that would look like in practice is being wargamed in Whitehall.
The benefit of this option is that it would allow the UK to appear to be more supportive of Present Trump than just simply allowing him to use a US airbase, and at the same time risking only a limited response from Iran. The UK is keen not to allow Tehran a pretext to strike British bases or interests and has sent extra assets to the region, with another six Typhoon jets sent to RAF Akrotiri in Cyprus, joining the eight already there.
The final option, considered the least likely, is full UK military intervention. Britain is still pushing hard behind the scenes for a de-escalation in the Middle East. The UK’s most favoured outcome is a diplomatic solution, in which both sides dial down the aggression.
Keir Starmer is also, as a politician, a gradualist and as such is considered less likely than some of his predecessors as prime minister to commit the UK military to support this kind of intervention, even if it is in the aid of one of our key allies, the United States.
