Cameron tests the water on Afghan front line
If it is December, it must be Afghanistan. With wearying inevitability, the pre-Christmas visit of a prime minister to the front line is now a fixed date on the political calendar.
David Cameron has come a little earlier than usual, taking advantage of a gap between votes on football and tuition fees to visit troops and test the water.
The context of this trip is not good. There has been the criticism of British forces by Afghan and US officials, made public via Wikileaks.
There has been a fake Taliban negotiator promoted, apparently, by MI6.
There has been the tragic killing by US forces of the aid worker hostage Linda Norgrove, and as the prime minister travelled out, the death by apparent friendly-fire of the 101st British serviceman to lose his life this year.
For all that though, the prime minister declares himself to be cautiously optimistic.
He is not the first prime minister to share this view, of course, and many hopes have been dashed since British troops first arrived here nine years ago.
But Mr Cameron says things are now different: There are 30,000 troops - US and UK - in Helmand, not the original 3,000.
There is a proper workable plan to tackle the Taliban.
And the training of Afghan police and troops is finally beginning to pay some dividends, despite the well documented problems - largely with the police - of corruption, drug addiction and incompetence.
Officials around Mr Cameron talk enthusiastically of poetry festivals taking place, music concerts, prisons working, bazaars opening and district governors actually doing their job.
Clearly they believe the tide is finally beginning to turn.
But David Cameron has another reason to sound so optimistic. His deadline of all British combat troops leaving Afghanistan by 2015 is a long way off.
His aim is to reassure the public that this conflict is not open-ended, but the risk is that people grow restless and ask why it is taking so long.
So, in the meantime they need reassurance that progress is being made, and that is why Mr Cameron is happy to predict that some troops at least will be home for Christmas. Next Christmas, that is.