Seeing relatives of the six British soldiers killed last week pay moving tribute to their loved ones brings home the courage and sacrifice of our armed forces and their families. But asking British personnel to risk their lives in Afghanistan is only justifiable if it's in the service of a clear and achievable strategy.
As the prime minister heads to Washington my concern is that he has an end date, but still no end state: no realistic vision of what will be left behind. And in these critical months the scale of military sacrifice does not appear to be being matched by diplomatic effort.
Afghanistan is becoming Britain's invisible conflict. David Cameron came to office promising Afghanistan would be his "number one priority", but it is now eight months since he made a parliamentary statement about it.
The government's most recent report states levels of violence have decreased year on year and "steady progress" is being made. You would not know from this brief, bland report that the UN claims the number of civilian casualties has risen for the fifth year in a row. Our troops have achieved tactical successes in Helmand, but there is little sign of the population shifting to support the Karzai government – which is central to the counter-insurgency strategy.
Why? In part because Afghanistan is seen as the third most corrupt state in the world, according to Transparency International surveys of local opinion. Yet the government's report hardly mentions corruption. There are serious concerns about ethnic tensions within the Afghan national security forces and there is still an urgent funding problem. The Foreign Office's reaction to a leaked Nato document on links between the Afghan Taliban and Pakistani security services was to dismiss it. The British people and our forces deserve straight talk, not warm words.
Perhaps most worrying at this stage is the danger of a disorderly rush for the exit as Nato countries announce unilateral and divergent withdrawal dates.
William Hague asserts British forces "will continue to perform combat roles until the end of 2014". The US defence secretary claims "by mid to the latter part of 2013 we'll be able to make a transition from a combat role" and the French president, Nicolas Sarkozy, announces his country's troops will leave by the end of 2013.
The suggestion that the British could be fighting for 18 months after key allies have already left should be cause for concern, yet it's hard to discern any serious diplomatic push to keep the mission together. Nor is there evidence that international partners are working effectively together to speed up the political process within Afghanistan. Conferences such as December's in Bonn come and go and more are planned, but few believe they will achieve the progress required in the time available. The Taliban's willingness to participate in a political office in Qatar is welcome, but there is little progress on a broader and more inclusive political settlement.
When the prime minister visits President Obama in Washington on Tuesday he must put Afghanistan back at the top of the agenda, stressing the importance of the diplomatic effort if we are to bridge the gap between where Afghanistan is and where it needs to be by 2014. We need a standing meeting of foreign ministers to lead on the political process and a serious attempt at closed door diplomacy on the scale of Camp David, Sunningdale and Wye River.
The west has diminishing control 0ver the Afghan endgame – leaving our troops increasingly exposed. The sacrifice of our forces will not be honoured unless more focus and determination is brought to the task of securing a lasting settlement that ensures Afghanistan never again threatens our security.
By Douglas Alexander, the shadow foreign secretary of the United Kingdom.