David Miliband: Multilateralism can only take us so far – we need the nation state

Most politicians are starting their speeches with quotations of Obama, and I want to do the same. He said, "the world has changed, and we must change with it".

Obvious, but it's important how you define the change, and I just want to say that three things define the change for me. One is global real-time interdependence, the second is the shift in the balance of power from governments and corporations to individuals. I call it the "civilian surge", and I believe that that shift brought about by the freedom with which information and ideas move around the world is very, very significant indeed. The third is the economic crisis, and in my judgment there are two very different forces pulling in opposite directions as a result of it. One force is pulling toward more nationalist protection. The opposite is a renewal of multilateralism.

It's not that "we're all multilateralists now", but unless multilateralism is renewed, we're not going to tackle these problems. If you think about most of the multilateral institutions, above all the UN, it was created to stop one state abusing the rights of another, and that remains an important function of a multilateral system.

However, the international system was not set up to take care of weak states. I spend a lot of my time thinking about Afghanistan and Pakistan. There is not an absence of multilateral engagement in Afghanistan. We've got a wide range of institutions seeking to support good governance by the Afghan government – no one wants Afghanistan as a new colony – rather to bolster a sovereign government.

We require a regularising of the strong states and their behaviour, and a supporting of weak ones. After that, the great insecurity is the absence of a mechanism to deliver public goods. Economic stability is a global public good and climate change (or rather its global mitigation) is a global public good. If you thought the world trade deal was a tough negotiation, climate change is much more complex.

There is a strong feeling in Europe that we need an era of responsible sovereignty to address all this. The nation-states are still the locus of political activity – they must know their limits, and know when to work together.

The Foreign Secretary was speaking at Chatham House on Tuesday