There have been four great moments in the modern age when statesmen have come together to reorder the world. In 1648 there was the Westphalia Treaty that followed Europe’s catastrophic Thirty Years War. Then 1815 saw the Congress of Vienna after the Napoleonic wars. And twice in the last century new global arrangements were made: disastrously in 1919 at Versailles and – most significantly – in the late 1940s, in a world wracked by war. The Bretton Woods Conference in 1944 signalled a breathtaking leap forward into a new world order. American visionaries helped form the United Nations, the World Bank and the International Monetary Fund (IMF). Not only that, but they put in place a policy of unprecedented generosity – the Marshall Plan. This transferred 1% of America’s national income each year for four years to the war ravaged economies of Europe – and saved the free world.

Now is the time for a fifth ‘great moment’, for reordering the world with reforms that will enable our international and regional institutions to do what they failed to do in the Rwandan genocide 15 years ago, and are failing to achieve even now in Darfur. We need to prevent conflict, to stabilise and then to reconstruct failing and failed states. Specifically we must be able to shield men, women and children threatened by genocide, ethnic cleansing, war crimes or crimes against humanity. The United Nations must become a consistent defender of the interests of all the world’s people. If confl ict is a threat to stability in specific areas of the world, climate change threatens the wellbeing of everyone. We must secure a new global climate change agreement with binding targets for all developed countries.

It must include an international carbon market – eventually generating up to $100 billion a year to fund ‘green’ development. I want to make the World Bank a ‘Green Bank’, focused on development and the environment, transferring billions in loans and grants to encourage the poorest countries to adopt alternative sources of energy. The Bank can provide an integrated approach to both poverty and global warming. We require similar global co-ordination on food, where we face the worst shortages for decades. And on disease and global pandemics where, led by the World Health Organisation, the priority is to improve early warning, increase stocks of global vaccine supplies and develop a more co-ordinated global response.

Globalisation can work if it is inclusive. Protectionism can be avoided only with open economies, free trade and flexibility accompanied by policies for fairness and justice. This requires policies that include investment in education and other social goods in the industrialised countries, and a new deal for the poorest countries. We must set new rules for a 21st century global economic system. We need a global trade deal that benefits rich and poor countries alike, and new international financial architecture and economic institutions that end the mismatch between global capital flows and only national supervision of them. I want to see the IMF acting as an early warning system for the global economy and we need a new deal as bold as the Marshall Plan between rich and poor.

As developing countries open up to trade, address corruption and pursue policies for economic development, so developed countries agree to make available new resources. In this way, the preventable diseases of TB, polio and malaria can be eradicated and for the first time in our history every child could enjoy education.

My vision is of a new World Bank and IMF, a reformed UN and strong regional organisations from European Union to African Union, able to bring the humanitarian aid, peacekeeping and support for stability and reconstruction that has been absent for too long. For the first time in history we have the opportunity to come together around a global covenant, to reframe the international architecture and build the truly global society.

This is an edited extract from the 2008 Kennedy Memorial lecture delivered by Gordon Brown on 18 April in Boston.