The International Monetary Fund and the World Bank have their 75th birthday this year, but the organisations that emerged from the Bretton Woods conference in 1944 are in no real mood to celebrate at their annual meetings this week. In Washington the mood is decidedly downbeat. Global growth is slowing; the conviction that low interest rates are here to stay is encouraging reckless behaviour and a dangerous build-up of debt; the climate-change clock is ticking louder. The threat of a new financial crisis is growing. The prospect of it being triggered by a climate emergency is real.

Yet the problems of the two Bretton Woods institutions run deeper than that. They are bodies created to foster international cooperation at a time when international cooperation is marked by its absence. Born out of the economic chaos of the 1930s, the IMF and the World Bank had a well-defined mission three quarters of a century ago: to rebuild war-shattered economies; to provide support to countries that ran into balance-of-payments difficulties; to limit currency turbulence; and to encourage the opening up of markets.

Now the IMF and the World Bank face an identity crisis. Put bluntly, what is the role for bodies dedicated to globalisation when globalisation has gone into reverse? The trade wars that have erupted over the past 18 months are not just causing damage to the world economy; they have damaged the credibility of institutions that failed to see the backlash coming, and, by buying into the free-market policies known as the Washington consensus, helped make it happen.

There are two possible ways forward. One is to say that the World Bank and the IMF are no longer fit for purpose and should be scrapped. This would be foolish, because many of the world’s pressing problems – global heating, money laundering, tax evasion, terrorism – can be solved only through international action. The answer is not to get rid of these institutions – multilateral bodies for all their flaws – but to give them a new sense of purpose.

The World Bank was set up to provide a steady stream of patient capital to help reconstruct western economies. Its mission now should be to help developing countries green their economies in exactly the same way. A lot more funding will be needed to ensure that the anti-poverty goals set by the United Nations can be met through sustainable growth.

In its original incarnation, the IMF saw its role as to provide member states with the policy space to pursue full employment and to increase spending on welfare. It backed capital controls to prevent governments being blown off course by currency speculation and saw fiscal policy – the use of taxes and public spending – as both a tool of economic management and of redistribution. If the populist revolt against globalisation has taught anything it is that growth without equity is unsustainable. Some parts of the IMF, the teams that piece together structural adjustment programmes for troubled countries, don’t always seem to get this.

In 1944, and for many years afterwards, the World Bank and the IMF were the international manifestation of the New Deal. They backed expansionary economic policies and social inclusion, and were mindful of the rights of individual countries to govern their own affairs. There are now proposals, backed by the UN, for a global Green New Deal. It would be a good thing all round – for the world economy, for the planet and for their own long-term prospects – if the IMF and World Bank chose to back the idea.