Optimists claim that the debacle in Cancún is just a temporary setback. As old trade hands were quick to point out, world trade summits have an unfortunate habit of failing: just cast your mind back to Seattle in 1999, Brussels in 1990 and Montreal in 1988. Eventually, though, negotiators haul the show back onto the road and a deal is clinched. It may happen again this time. But what if the acrimonious breakdown of the World Trade Organisation’s Doha round last September is actually much more serious? We cannot afford to be complacent. If the WTO is in serious trouble, the consequences could be devastating not just for international trade, development and the world economy, but also for multilateralism and global progressive politics.