Cameron raises awkward questions for Obama
President Barack Obama hasn't sat down to talk to David Cameron in Canada yet, but the UK prime minister may have turned it into a rather awkward affair. The prime minister's comments about withdrawing troops from Afghanistan are bound to alarm the White House.
Mr Cameron has said that British troops should be out of Afghanistan before the next election in five years' time. "We can't be there for another five years, having been there for nine years already."
Some reckon this question will define the Obama administration. At any rate, it is going to be the big question on Capitol Hill next week, when Gen David Petraeus will face senators in a hearing to confirm his new role in Afghanistan. They will want to know how strongly he backs the president to start bringing some troops home by July next year.
But the president has never talked about a date to withdraw all American troops. The unspoken assumption is that's because that would be in a distant future. I seem to remember Hillary Clinton once remarking that there are still American troops in Germany, although World War II has been over for more than half a century.
It does more, though, than raise awkward questions. Britain is the United States's biggest partner in Afghanistan, by far. If all UK troops withdraw, the Americans could be left just about alone.
No doubt contributions from others will provide some fig leaf but the feeling that the US is on its own could cause resentment among the American public. We haven't yet had any White House reaction, but my guess is that this is a very unwelcome intervention ahead of the first official meeting between prime minister and president.