Seven years after they started, the Doha Round of trade talks broke up this week without agreement. That is a misfortune; it need not be a disaster. The failure will be measured in potential economic gains that will not now be realised, when the world economy is under pressure from the credit crunch and soaring commodity prices. But the costs can be mitigated if there is a renewed commitment by the developed countries to the principles of a liberal trading order.

The Doha Round has collapsed because of what might appear technical disputes over market access. Most notable among these are divisions about agriculture. Developing countries complain of the maintenance of farm subsidies in the rich world while the US accuses China and India of “blatant protectionism”.

In theory, an earlier, more sweeping offer by the EU and the US to cut agricultural subsidies might have given impetus to negotiations. On the other side, it is odd that China and India proved reluctant to reduce agricultural tariffs when their people face sharp increases in food costs. A deal might have been achieved. It will, at best, not now be attainable until after a new US president has taken office.

The strict financial costs of a failure to reach agreement have been variously assessed. A commonly cited figure is an estimate by the World Bank that removing agricultural tariffs and subsidies would boost exports globally by $300 billion a year by 2015. But the potential increments to growth from this deal are less significant than the political symbolism of its collapse.

The international trading order is among the most important achievements of postwar diplomacy. Cordell Hull, the US Secretary of State under Franklin Roosevelt, is regarded as the father of the multilateral trading system. He won the Nobel Peace Prize for his work in establishing the United Nations but he considered that an open trading regime was just as important for world peace.

The eight rounds of trade negotiations under the auspices of the General Agreement on Tariffs and Trade from the early 1960s reduced tariffs in developed countries to an average of less than 4 per cent. Many quotas and subsidies were lowered. Consumers in the developed countries benefited from cheaper goods. Poor countries that integrated themselves into the world economy were able to industrialise rapidly. The creation of the World Trade Organisation in 1995 and the generally successful working of its disputes mechanism have cemented these gains further.

The risk is that failure to advance multilateral negotiations in the Doha Round will spur the negotiation of bilateral or regional trading agreements as an alternative. These grant preferential access to markets. By definition, they create losers, namely the countries excluded from the deals. The message should be emphasised by European leaders, especially as Barack Obama has apparently not yet weaned himself off the traditional Democratic suspicion of free trade. Trade talks are about more than getting and spending. Trade liberalisation is not a zero-sum game, in which there must be relative losers as well as relative winners. It is a positive-sum venture in which global living standards rise - to the particular benefit of the developing world.