The foreign secretary William Hague said last week that human rights should be the "irreducible core" of the UK's foreign policy. But he did not spell out why, or what that would mean in practice.
Ethical arguments aside, there are three practical reasons for having a human rights-friendly foreign policy. irst, promoting human rights and the rule of law is a good way of securing some of the UK's most important foreign policy objectives, including preventing armed conflict, political extremism and radicalisation, and fostering economic development and political stability.
Second, championing respect for human rights and the rule of law sets a good example and is good for the UK's international reputation. That in turn helps to maintain the UK's political and diplomatic clout around the world - what Hague call's the UK's "soft power". Arguably that is even truer now that "hard" economic power is shifting rapidly eastwards towards nations such as China, which have little interest or experience in promoting human rights. If the UK can no longer justify its seat at the top table through economic and military might, then it should rely instead on its support for human rights.
And third, the UK is involved in a multifaceted struggle against Islamist militancy on several fronts. Experience has shown that this struggle cannot be won by military means alone. The ideological battle for hearts and minds is just as important, and victory on that front depends on the strictest adherence to human rights standards and the laws of war.
The more difficult question is how a country such as Britain, gripped by economic crisis and the consequent loss of self-confidence, should go about promoting human rights and the rule of law around the world. Why should others listen to what the UK has to say on human rights?
Hague seems to have grasped one of the problems here when he said in his speech, "We should always strive to act with moral authority, recognising that once that is damaged, it is hard to restore."
Hague was doubtless referring to the damage that the UK has done to its international standing and to its credibility as a champion of human rights by the last government's whitewashing of US torture policies, by the involvement of British military forces in abuse in Iraq, and by the alleged complicity in torture in Pakistan and possibly elsewhere.
So the first task is for the UK to clean up its act. Prime Minister David Cameron's announcement this week of a judge-led inquiry into allegations of UK complicity in torture and rendition is a positive step in that direction. The inquiry needs to be demonstrably independent, comprehensive, and as public as possible. Without a serious exercise in self-examination, transparency and accountability, there's little chance that the UK will be taken seriously when it speaks out on human rights.
The second thing the UK needs to do is make sure that in future its voice on human rights is consistent. The last government was quick to condemn the human rights abuses of its opponents but reluctant to criticise those of its allies.
One area where the new government might signal a shift of policy is in its approach to abusive governments that are recipients of UK development assistance. Perhaps inhibited by the large sums of aid it had given to them over the years for economic development, the Labour government was reluctant to acknowledge, let alone criticise increasingly serious abuses by such states as Rwanda and Ethiopia over recent years.
The change of government is a good opportunity to start putting pressure on those countries to stop the slide towards repression. There may be an argument for ring-fencing the aid budget. But there's no reason why the hard-pressed UK taxpayer should be bankrolling authoritarian governments - in the long run, such a strategy will not achieve economic development and stability.
A third area where the UK could exercise greater leadership is in promoting and protecting international criminal justice. The UK was at the forefront of efforts to secure accountability for war crimes, crimes against humanity and genocide, culminating in the establishment of the International Criminal Court. But today there is push back from some political leaders determined to avoid accountability. Furthermore, the credibility of international justice is threatened by the lack of accountability for war crimes in places like Sri Lanka, Gaza and Burma, where the ICC lacks jurisdiction and the UN Security Council will not use its power to activate it. The UK should signal its firm commitment to accountability for grave international crimes - and it should start by resisting pressure to water down its own rules for prosecuting such crimes in British courts under the principle of universal jurisdiction.
Of course, Afghanistan is likely be a real test of whether Hague can turn into action his declaration that human rights will be the "irreducible core" of his foreign policy. In the coming months and years, the temptation for the UK and the US in Afghanistan will be to focus on narrow expediency and self-interest, to cobble together deals and forget about human rights.
But will that serve the UK's or the US's long-term interests? History suggests not. Protection of human rights is not a panacea for the problems of Afghanistan and its neighbours. But ignoring human rights - ignoring the plight of women and children and the principle of accountability for war crimes, turning a blind eye to torture and civilian casualties - is a recipe for failure and further instability.