Despite much loose talk about the new global economy, today's international economic integration is not unprecedented. The 50 years before the first world war saw large cross-border flows of goods, capital and people. That period of globalization, like the present one, was driven by reductions in trade barriers and by sharp falls in transport costs, thanks to the development of railways and steamships. The present surge of globalization is in a way, a resumption (恢复) of that previous trend. The earlier attempt at globalization ended abruptly with the first world war, after which the world moved into a period of fierce trade protectionism and tight restrictions on capital movement. During the early 1930s, America sharply increased its tariffs, and other countries retaliated (报复), making the Great Depression even greater. The volume of world trade fell sharply. International capital flows virtually dried up in the interwar period as governments imposed controls to try to insulate (隔离) their economies from the impact of a global slump. Capital controls were maintained after the second world war, as the victors decided to keep their exchange rates fixed on arrangement known as the Bretton Woods System, named after the American town in which it was approved. But the big economic powers also agreed that reducing trade barriers was vital to recovery. They set up the General Agreement on Tariffs and Trade (GATT), which organized a series of negotiations that gradually reduced import tariffs. GATT was replaced by the World Trade Organization (WTO) in 1995. Trade flourished. In the early 1970s, the Bretton Woods System collapsed and currencies were allowed to float against one another at whatever rates the markets set. This signaled the rebirth of global capital market. America and Germany quickly stopped trying to control the inflow and outflow of capital, Britain abolished capital controls in 1979 and Japan (mostly) in 1980. This is part of the reason why continental Europeans tend to worry more about the power of global capital markets. America has been exposed to them for much longer. Two forces have been driving these increased flows of goods and money. The first is technology. With the costs of communication and computing falling rapidly, the natural barriers of time and space that separate national markets have been falling too. The second driving force has been liberalization. As a result of both the GATT negotiations and unilateral (单方面的，单边的) decisions, almost all countries have lowered barriers to foreign trade. Most countries have welcomed international capital as well. One of the driving forces of today's globalization is ______ .