Kamlesh Sharma, Sec Gen

Food, fuel, and finances. In those three thoroughly globalised markets today, the world is being reminded of its levels of dependency and the inadequacy of current arrangements for managing their volatility.

These and other great current challenges - climate change and global poverty - demand more, not less, international cooperation. They demand more, not less, effective international institutions.

Just over sixty years ago, there were similar convulsions of economic uncertainty and turmoil in the wake of two appalling wars. In the 1940s, a shattered world set about rebuilding itself. It spoke as one about the human values that needed to be protected and promoted, and about the means of doing so. It had the political will to do something practical and durable.

Embodying the hopes of a better post-war world was a set of new international organisations, headed by the United Nations. In a supporting role, charged with providing prosperity, were Bretton Woods institutions - notably the World Bank and International Monetary Fund.

Times have changed. Today's global community would barely be recognisable to the architects and builders of those global institutions of the 1940s. Eighty sovereign independent states have become two hundred. The world's population has risen from 2.5 billion to 6.5 billion. The G7's share of world income has fallen to just 40%, and the decline continues. The centre of economic gravity has shifted from the Atlantic Ocean, with the Asia-Pacific region now accounting for two-thirds of global GDP. The USA was the world's largest creditor nation then; it is the world's largest debtor nation now.

Change has been unstoppable, and so too the process of integration. The benefits of trade, culture and technology now cross borders as easily as disease, climate change and environmental degradation, terrorism, rising prices and financial turbulence.

It is time to rebuild again. No one today would use a 1940s telegram when they can use a 2008 mobile phone. We need the same leap for the global institutions to make an international system fit for the 21st Century.

This does not mean scrapping the legacy, achievements, ideas and talent of those bodies from the 1940s. But it does mean reforming them, on at least three fronts.

First, in their activities. The IMF's policies have shifted unevenly from fixed to floating exchange rates, from controlled to free capital flows. Its prescriptions of austerity are uneven. It needs now to be more responsive and accountable to states that are small, vulnerable or lagging behind. The IMF has a reform plan in hand, even if it doesn't yet go far enough. The World Bank also needs to advance down this track, upon which its future credibility depends.

Second, we need coherence. There is a proliferation of agencies and organisations within the United Nations system, but development goals remain distant. The UN's membership has recognised this, and has expended energy and time on devising reform plans. There may be weaknesses in those plans, but the fundamental deficit is the will to implement them, forging deeper and faster UN reform.

The environment is the bedrock of human development and wellbeing. Yet the international institutions we have in place comprise 500 or so multilateral environmental agreements. They are like a dysfunctional spider's web with overlap, duplication, and areas without coverage at all. The result is that the true value of our environment has been overlooked and irreparably damaged. The leading agency, the UN Environment Programme, is circumscribed and weakly funded.

Third, the world needs improved governance in its global institutions. They need to be representative of all; accountable to all; delivering for all; responsive to all; and legitimate in the eyes of all.

The Commonwealth is one of the oldest international organisations in the world, with its origins dating back more than a century. Its success lies in its ability to evolve and remain relevant and responsive to the needs of its membership at any time in history. In its diversity, it is a template of the wider world.

Its success lies in its shared values and its collective way of doing business and expressing itself. It is home to a third of the world's population, across five continents. It brings together governments, civil society, professional associations, business, and many others of all ages and interests. It is a recipe for inclusion and success.

A group of Commonwealth Heads of Government met recently in London. They represented the geographical, economic and cultural diversity of the Commonwealth and the world. They gathered with a sense of urgency to review the health of the UN, the Bretton Woods institutions, and the current arrangements under which the environment is managed. Those leaders drew up an ambitious plan. They will give political momentum where reform is under way and new impetus where it is needed. Their approach is to build, not to dismantle.

Their aim is to develop a global consensus, just as existed in the 1940s, to create a new environmental governance structure through a world gathering that can start with a clean sheet of paper. They want to incite UN reform. And they are pursuing a fundamental rewrite of the IMF and World Bank in a new Bretton Woods-style conference.

No one group - not even the Commonwealth - can carry this reform effort alone. But a quarter of the world's countries can stir the imagination of the rest. The new world of the 21st Century expects nothing less. Without such reform, the lives and welfare of people all over this planet will become even more endangered than they already are.  

By Kamalesh Sharma, Commonwealth Secretary-General