David Cameron left Washington this morning after a two-day visit in which he has enjoyed the warmest possible embrace from America's political and social elite.
The prime minister has won plaudits from President Barack Obama, who last night described him as "just the kind of partner that you want at your side" and even compared their relationship to that between Churchill and Roosevelt.
And at a glittering state dinner at the White House, he and wife Samantha rubbed shoulders with Hollywood's George Clooney, as well as the British stars of TV hits like Downton Abbey and Homeland.
Mr Cameron achieved his political goal of demonstrating that the UK and US are "in lockstep" on the timetable of withdrawal of troops from Afghanistan, as well as sharing the goal of ramping up political and economic pressure on Syria and Iran.
And he secured Mr Obama's agreement for officials from both sides to meet to review the operation of the UK's controversial extradition treaty with the US. This comes after recent controversies - like that of Christopher Tappin.
In contrast to the 2009 visit by Mr Cameron's predecessor Gordon Brown, the President made a point of repeatedly stressing his regard for the "essential relationship" between Britain and the US.
And Mr Cameron told last night's dinner he felt the special relationship between the transatlantic allies "in my bones".
Proposing a toast to his hosts, Mr Cameron praised Mr Obama for his "strength, moral authority, and wisdom".
In comments which appeared to invite comparison with President Obama's predecessor George W Bush, the PM said: "Barack has not rushed into picking fights, but is steward of America's resources of hard and soft power. He's taken time to make considered decisions, drawing down troops from Iraq and surging in Afghanistan."
In an apparent reference to the Camerons' disabled son Ivan, who died aged six in 2009, Mr Obama praised their "strength" as parents.
And Mr Cameron said: "As fellow parents, Barack and Michelle have both been personally very kind to Sam and me.
"And as fellow leaders, we've struck up, I believe, a really good partnership.
"It is frank and honest. We talk through issues very rationally. We don't need to remind each other of the basic threats that we face; we know them.
"But there are three things about Barack that really stand out for me: strength, moral authority, and wisdom."
After saying his farewells at the White House this morning, Mr Cameron flew on to New York, where he will pay an emotional visit to Ground Zero and take questions from university students.