After Sir Keir Starmer's victory, what next for the 'special relationship'?

Number 10's newest advisers will have been busy re-drafting the briefing notes marked "special relationship".

It's awkward.

When the prime minister steps off a plane in Washington DC this week - for NATO's 75th anniversary summit - he'll step into the middle of a US political drama with a conclusion no one can call.

Joe Biden is his host, but for how long? Sir Keir knows he could be shaking a dead man's hand.

His first top-level meeting with the sitting president could be his last, given the doubts that Mr Biden will make it to next week, politically, never mind November's election.

The US brief demands three-dimensional diplomacy built around Biden, the Democrat who might replace him and the Republican who could replace both - Donald Trump.

For Starmer, Trump 2.0 would be complicated.

The new PM is aligned with current White House thinking on Gaza, Ukraine and NATO.

That will aggravate conversations with Team Trump, as will a UK "reset" re: China that doesn't necessarily square with Trump's belligerence towards Beijing - he will want allies to fall into line.

Beyond the policy agenda, there is the fundamental matter of political philosophy.

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Over the years, UK-US relations have been built on shared democratic ideals and values. It's the "given" that's underpinned the bond through the years.

With a Trump re-election, it would be given the stress test that Starmer doesn't need.

Whatever the change at Number 10, the American end of the special relationship will determine just how special it is.

No change there.