This Christmas the world economy offers few reasons for good cheer. As credit contracts and asset prices declined, demand across the globe is declining. Rich countries collectively face the severest recession since the Second World War: this week’s cut in the target for the federal funds rate to between zero and 0.25% shows how fearful America’s policymakers are. And conditions are deteriorating fast too in emerging economies, which have been exhausted by declining exports and the drying-up of foreign finance. This news is bad enough in itself; but it also poses the biggest threat to open markets in the modem era of globalization. For the first time in more than a generation, two of the engines of global integration -- trade and capital flows -- are shifting into reverse at the same time. The World Bank says that net private capital flows to emerging economies in 2009 are likely to be only half the record $ 1 trillion of 2007, while global trade volumes will shrink for the first time since 1982. This twin shift will force adjustments. Countries that have relied on exports to drive growth, from China to Germany, will slump unless they can boost domestic demand quickly. There is a risk that in their discomfort governments turn to an old, but false, friend: protectionism. Integration has less appeal when pain rather than prosperity is hanging across borders. It will be tempting to support domestic jobs and incomes by diverting demand from abroad with export subsidies, tariffs and cheaper currencies. The lessons of history, though, are clear. The economic isolationism of the 1930s cruelly intensified the Depression. To be sure, the World Trade Organization (WTO) and its multilateral trading rules are a bulwark(壁垒) against protection on that scale. But today’s globalised economy, with far-stretched supply chains and just-in-time delivery, could be disrupted by policies much less dramatic than the Smoot-Hawley act. A modest shift away from openness -- well within the WTO’s rules -- would be enough to turn the recession of 2009 much nastier. Increased protection of that sort is, alas, all too plausible. Recession in rich and emerging markets is not only a bad news, but also threatens ______.