Debates and protests about globalization have been muted since last September's terrorist attacks. But that silence does not mean that they are over. Indeed, protests about globalization seem likely to return with more normal times. When they do, our understanding of the process will be greater if we look back at history.

Among historians, globalization provokes a keen sense of déjà vu : we were here a century ago. Great achievements - material progress, dizzying new technologies such as the automobile, the telephone, the typewriter - existed back then, but also protests against a world that seemed out of the control of traditional political institutions.

Then, as now, the backlash came chiefly from rich industrial countries, rather than from poor peripheral countries which were often seen as the objects of capitalist exploitation. It was advanced countries that imposed tariffs against "unfair" competition from abroad. Central banks were instituted with the responsibility of managing disorderly capital flows. Migration policy became more restrictive, as some big recipients of immigration began to debate selectivity in their choice of immigrants.

The process of integration was reversed after the WWI and finally destroyed in the Great Depression, in a series of vicious shocks: tariff protection, contagious financial panics that spread from the periphery to the heart of the world's financial system, and a turn to economic nationalism and autarky. What had before 1914 been safety nets against excessive globalization became after the WWI gigantic snares which strangled the world economy.

The most remarkable characteristic of globalization backlashes is how they create an odd alliance of right and left. In the late 19th century, Europe's land-based aristocracy was weakened by the competition of cheap grain and other foods shipped across the oceans. As farm prices and rents fell, aristocracy faced decline. So it mobilized small-scale farmers, artisans, and small producers who shared the landed elite's belief that unfettered competition was harmful. For these groups, globalization amounted to redistribution.

On the left, the growing working class sought to use political power to change economic relations - to advance more progressive tax policies, or to stop the use of tariffs to protect the old order. Progressives also decried international capitalism's undermining of labor standards. The German sociologist Max Weber made his reputation with warnings of the dire consequences of further Polish immigration to Germany. "There is," he wrote in an echo of today's globalization debates, "a certain situation of capitalistically disorganized economies, in which the higher culture is not victorious but rather loses in the existential fight with lower cultures."

In the center - beleaguered by the anti-global reactions of left and right - a liberal commercial elite saw the products of economic opening or globalization as wholly beneficial. Instead of a two part split between left and right, there was thus a triple division, between anti-globalization conservatives, pro-globalization liberals, and re-distributionist leftists.

When the extremes of the political spectrum became radicalized, as they did in the interwar period - the anti-international right moved to fascism, the left to communism - democratic politics became paralyzed.

For much of the post-1945 period, these divisions disappeared as right and left fought battles for redistribution within national economies. The old triple polarization only returned with the new wave of globalization. Again, there is an anti-international right that has come to play some role in all the major industrial countries, and that tries to defend existing prosperity and property rights from the vagaries of international markets.

The protectionist anti-globalization impetuses of the left are less visible in political parties than in labor movements, but these can shape political programs. For unions, the new right is a competitive challenge for support. For their members, international competition is a major threat as imports or immigrants may cut the wages of less skilled workers. Consequently a demand for the exclusion of the products of "unfair competition" is transmitted to main-stream center-left parties, such as the French Socialists or America's Democrats. Fear of lowered wages plays into a broader coalition based on umbrella anti-globalization resentments directed against multi-national corporations and international financial institutions.

In the modern center is something similar to the endangered liberal order of late 19th century Europe: the political movement of an elite that espouses globalization because it benefits from it. This is the group that cynics have termed "Davos man."

It is hardly likely that such a program - presented in these terms - can ever command massive electoral popularity. The costs of globalization, and the resentments that it generates, are too obvious. This type of party, committed to simple liberalization and opening, rarely moves beyond the range of five to ten percent of the vote that Germany's liberal Free Democrats attracts. When Leszek Balcerowicz's Freedom Union in Poland won 13% of the vote in a parliamentary election in 1997, this represented a stunning success. But in Poland's elections of last year the Freedom Union received less than 5% of the vote - much closer to a "normal" level of support for a liberal political movement.

This new politics incites wide feelings of malaise and helplessness. The old movements of the 20th century are largely exhausted: classic conservatism because the world changes too rapidly for conservatism as stasis to be coherent or appealing; classic socialism because the rapidity of change erodes traditional labor positions in exactly the same way.

The bankruptcy of these two respectable but now out-moded positions opens the door for a new populism, based on an anti-globalization groundswell. The new/old politics is inward-looking and likes the idea of the revival of the nation as a protective bulwark against foreign goods and foreign migrants and foreign ownership. It is also dangerous and destructive, and was in large part responsible for Europe's hideous politics in the first half of the 20th century.