Imagine that an American soldier left a US military base on British soil in the middle of the night, carrying a gun. Imagine that this soldier killed 16 innocent civilians in a nearby village. Imagine that nine of those civilians were children. Then imagine how we would react if we were told that he would not be subject to British law, but instead spirited home to be put before an American court martial.
Not any of this has happened in Britain, thank God. But just such a massacre took place in Afghanistan over the weekend. You can see why the Afghan people would want the accused man to face trial under their system; you can see why they might interpret his removal to the US as a sign of Washington's contempt for their law and for their lives.
The Kabul parliament has called for this soldier to be tried in Afghanistan, but the Afghan government has signed up to a legal framework that means the US is quite within its rights to put the man through its system, instead.
And yet there is still the ugly sense of a double standard. The legal questions might be knotty in the UK, too, but there seems little doubt that diplomatic will would ultimately prevail. Even if it refuses to be a part of the International Criminal Court, in most countries, the US accepts that off-duty soldiers committing serious crimes should come under the jurisdiction of the local system.
Afghanistan is not like most countries. But the US is always talking about its respect for Afghan sovereignty; just as in Iraq, the prevailing rhetoric of the endgame is that for us to stand down, they must stand up. Here is a meaningful opportunity to demonstrate commitment to that principle, to pre-empt the Taliban's rhetoric – and to prove that the expressions of sorrow that we've heard in recent days aren't merely designed with US interests in mind.
An Afghan trial is almost certainly not going to happen: the demands of realpolitik are too great and it is true that it is hard to see such a trial being conducted fairly. But what about a compromise: a joint tribunal conducted in Afghanistan, open to the Afghan public, and attended by Afghan legal representatives?
If such an idea is really beyond the pale, then one has to question whether the airy assurances that the country won't implode when Nato forces leave can carry any weight. And if even this argument doesn't move you, consider this: not an imaginary American soldier in Kent, but an imaginary Afghan soldier in Kansas. The US wouldn't dream of selling its citizens out by allowing a foreign country control over the fate of the person accused of their murder. And the rest of the world wouldn't dream of asking that it do so.Follow @archiebland