Interdependence — the fact of a crisis somewhere becoming a crisis everywhere — makes a mockery of traditional views of national interest. Nations, even as large and powerful as the USA, are now affected profoundly and at breakneck speed by events beyond their borders.

Why is immigration now the top domestic policy issue in much of Europe and in the US? Because globalisation is making mass migration a reality — and only global development will make it a manageable reality.

Why has energy policy, too, rocketed up national agendas? Because of the need for countries like China and India to fuel their rapid development and the threat of climate change. The solution lies in an internationally agreed framework through which the developing nations can grow, the wealthy countries maintain their standard of living and the environment be protected from disaster.

So you can’t have a coherent view of national interest today without a coherent view of the international community. These challenges affect us all and can only be effectively tackled together. And we can’t wait around to see how these global challenges may develop as we could it the past. They require a pre-emptive, not simply a re-active response, on the basis of precaution not just certainty , often outside our own territory.

For the terrorism we are fighting in Britain, wasn’t born in Britain, though on 7th July last year it was British born terrorists that killed people. The solution lies in schools and training camps and indoctrination thousands of miles away, as well as in the towns and cities of modern Britain. The solution to mass migration lies at its source, not in the nations feeling its consequence.

But common action will not be agreed unless it is founded on common values — of liberty, democracy, tolerance, justice. These are the values universally accepted across all nations, faiths and races, though not by all people within them. These are values that can inspire and unify. We need an international community that both embodies and acts in pursuit of these global values.

The scale of the agenda in front of us is enormous. And, increasingly, there is a hopeless mismatch between the global challenges we face and the global institutions to confront them. After the Second World War, people realised that there needed to be a new international institutional architecture. In this new era, in the early 21st century, we need to renew it.

In A speech in the United States on Friday, I made some tentative suggestions for change. First, the UN Secretary General, Kofi Annan, has done an extraordinary job in often near impossible circumstances and deserves backing for his reform programme. But a Security Council which has France as a permanent member but not Germany, Britain but not Japan, China but not India to say nothing of the absence of any representation from Latin America or Africa, cannot be legitimate in the modern world. If necessary let us agree some form of interim change that can be a bridge to a future settlement.

We should strengthen the UN Secretary General’s powers to propose action to the Security Council for the resolution of long-standing disputes and encourage him to do so.

Second, the World Bank and IMF. There is a case, as has been argued before, for merger but, in any event, there is certainly a powerful case for reform including a radically improved relationship with developing nations and more representation for the emerging economies.

Third, there is a strong argument for establishing a multilateral system for “safe enrichment” for nuclear energy. The IAEA would oversee an international bank of uranium to ensure a reliable fuel supply for countries utilising nuclear power without the need for everyone to own their own fuel cycle.

Fourth, the G8 now regularly meets as the G8 +5. That should be the norm.

Finally, we need UN Environment Organisation to match the importance the issue now has on the international agenda.

I do not under-estimate the hazardous task of achieving these changes. But I also know the main obstacle. It is that in creating more effective multilateral institutions, individual nations have to yield up some of their own independence.

Powerful nations want more effective multilateral institutions but only when they think those institutions will do their will. What they fear is effective multilateral institutions that do their own will.

But if there is a common basis for working — agreed aims and purposes — then no matter how powerful, countries gain from being able to sub-contract problems that on their own they cannot solve. Their national self-interest becomes delivered through effective communal action.

Today, after all the turmoil and disagreement of the past few years, there is a real opportunity to bring us together — to tackle global terrorism, to ensure a healthy global financial system, provide secure and clean energy and to heal long-running disputes including, crucially, progress towards a two-state solution to the Israeli/Palestinian conflict. We all have an interest in stability and a fear of chaos. That’s the impact of interdependence.

I believe, too, we all have a strong common interest in supporting democracy in Iraq. I don’t want here to justify the original decision or reopen past arguments. I do want to advocate a new concord to displace the old contention.

It is three years since Saddam left office, three years of strife and bloodshed. But despite all the terror, a democratic political process has grown. Last week, I visited the new Government in Baghdad, chosen freely by the Iraqi people, Sunni, Shia, Kurds and non-aligned. I heard from these leaders not the jarring messages of warring factions but one simple, clear and united discourse. They want Iraq to be democratic, its people to be free. They want to tolerate difference and celebrate diversity and the rule of law not violence to determine their fate.

The war split the world. The struggle of Iraqis for democracy should unite it.

You may not agree with original decision. You may believe mistakes have been made. But if Iraqis can show their faith in democracy by voting for it, shouldn’t we show ours by supporting them in it?

This should be a moment of reconciliation not only in Iraq but in the international community. For their struggle is a wider struggle. The purpose of terrorism in Iraq is to defeat not just Iraqi democracy but democratic values everywhere.

From the moment the Afghans came out and voted in their first-ever election, the myth that democracy was a Western concept was exploded. The Governments of the world do not all believe in freedom. But the people of the world do.

In my nine years as Prime Minister I have not become more cynical about idealism. I have simply become more persuaded that the distinction between a foreign policy driven by values and one driven by interests is obviously wrong. Globalisation begets interdependence. Interdependence begets the necessity of a common value system to make it work. In other words, the idealism becomes the realpolitik.

Our values are our guide. To make it so, however, we have to be prepared to think sooner and act quicker in defence of those values — progressive pre-emption, if you will.

None of that will eliminate the setbacks, fallings short, inconsistencies and hypocrisies that come with practical decision-making in a harsh world. But it does mean that the best of the human spirit which, throughout the ages, has pushed the progress of humanity is also the best hope for the world’s future.