David Miliband will attempt to recast British foreign policy in the post-Iraq era tonight, arguing that mistakes there and in Afghanistan should not derail the moral imperative to intervene abroad in the pursuit of spreading democracy.

The Foreign Secretary will cite China's growing power as a warning that “we can no longer take the forward march of democracy for granted” and urge that Britain renew its commitment to those fighting for democracy under autocratic regimes abroad.

In his speech in Oxford, in honour of the jailed Burmese democracy leader Aung San Suu Kyi, he will refer to the “civilian surge” of thousands of pro-democracy demonstrators who met with brutal repression on the streets of Rangoon last September.

“I am unapologetic about a mission to help democracy spread through the world,” he will tell his audience at St Hugh's College.

Debate and disagreement over the bruising military experience in Iraq had “clouded the debate about promoting democracy around the world. I understand the doubts about Iraq and Afghanistan and the deep concern at the mistakes made. But my plea is that we do not let division over those conflicts obscure our national interest, never mind our moral impulse, in supporting movements for democracy.”

Mr Miliband's message may be heard most keenly in China. He is due to visit the country in a fortnight's time and anchored his thesis against the “end of history” world view around it, noting that “since the Millennium there has been a pause in the democratic advance”. China should not fear democracy as “a threat to stability but a way to guarantee it”.

In weak states, he says, “there are no military solutions to the insecurity and injustice that helps to breed terrorism, only political solutions”. He does not mention Pakistan but must be thinking of the troubled nation heading to polls next week when he gives warning that “without democratic legitimacy, it is hard to sustain the increase in state capacity needed to maintain law and order”.

The Foreign Secretary offers five practical suggestions on how Britain can promote and support democracy abroad. Supporting the development of a free media, as well as the BBC's own tradition as a trusted information source across the globe, will help to provide democracy advocates with the knowledge and exposure they need, he says.

Encouraging greater economic openness and promoting trade with countries such as China could be instrumental in opening them up to political and social change. As a big provider of aid, Britain can wield huge influence in supporting projects that lend support to civil society and help to build independent institutions.

Holding out the carrot of membership of international alliances such as the European Union and Nato can be a powerful tool in persuading states to adopt democratic values, he says.

A common agreement on the democratic standards required for membership would help to formalise this and provide an accepted standard that could be adopted by other regional alliances. Sanctions and the use of military force are the last weapons in the pro-democratic arsenal.

Mr Miliband's staunch defence of the universal value of democracy springs from his concern that recent global turmoil has seen Britain slide into an increasingly isolationist posture. The mistakes made in Iraq, and the fresh concerns over Afghanistan's future, as well as the violence in countries such as Kenya previously hailed as beacons of success, have seen a creeping loss of faith in democracy as a universal panacea.

The Foreign Secretary believes the case for the universal value of democracy needs urgent restating without recourse to the kind of American neo-conservative rhetoric so out of favour with much of the world.

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