Your editorial (22 May) is an important contribution to a major global event. But the article misses one point. Over the last 200 years free trade has been demanded by the dominant world power. All the major powers today in Europe and North America protected their infant industries in the 19th century at their development stages of growth. Once these powerful and imperial nations had developed their new technologies, they demanded free trade from weaker nations. After the second world war free trade was managed by the dominant powers through the IMF. The shift in American politics to protect its industries is a major indicator that the days of US dominance are coming to an end. This move will not be lost on the poorer nations, as they too will wish to protect their young industries as they move to industrialise. This is a move of greatest importance in world politics, and the Guardian was right to emphasis this vital change. The world is changing in ways we could not have predicted 10 years ago. Dr Roger van Zwanenberg London