Perhaps you remember freshman year in college, dozing through a Christ-to-Khrushchev survey course on Western history, when suddenly Prof. Whatwashisname mentioned the Peace of Westphalia and a groan rose from the soles of your penny loafers: another damned date to memorize.

Why disturb the dust on such memories? Because Sunday's elections in Germany are among the most important in postwar Europe, and Germany's past is always tangled up in the present.

The Peace of Westphalia (1648, ended the Thirty Years War) ratified the existence of more than 300 sovereign German principalities. That suited the princes, and the national interest of Germany's rivals. But it retarded the evolution of a mature German nationalism. France and Britain were nations in the 1400s; the United States was a nation in the 1700s; Germany was not a nation until the second half of the 19th century. Today German nationalism, always problematic, is a force on the left, associated with neutralism--the escape from history and geography.

Most Germans do not think constantly about--or vote in consequence of --the proposed deployment of modernized intermediate-range missiles. The crucial issues are the condition of the economy and the social security system. But the Social Democratic Party under Hans-Jochen Vogel has moved radically leftward, partly pulled by competition with the Greens, partly by latent inclination. (Three decades ago the SPD opposed rearmament and the European Defense Community.) The SPD now opposes deployment by NATO of missiles to counter the Soviet SS20s--a deployment first urged upon NATO by the last SPD chancellor, Helmut Schmidt.

It is unlikely the SPD could do well enough for Vogel to govern other than in coalition with the Greens, who would deepen the SPD's neutralist predisposition. With some SPD members now talking about "security partnership" with Moscow, Moscow would seize upon an SPD-Green victory to connect nationalism and neutralism. Moscow would offer some form of cosmetic "reunification" of Germany in exchange for movement toward the left's fantasy of Germany-as- Switzerland. Even if Chancellor Helmut Kohl wins, one thing has been changed, radically and perhaps irrevocably, and one substantial danger will remain.

What has changed is the SPD. Schmidt held it to what can be called Bevinism, named for Ernest Bevin, foreign secretary in Britain's postwar Labor government. Bevin was a fiercely anti- Soviet socialist. (He favored using armor to break the Berlin blockade.) A decisive event in the growth of postwar German democracy was the SPD's adoption of the Godesberg platform in 1959. In it, the party formally disavowed its Marxist past and class orientation, put aside dogmatic anti-military doctrines and endorsed socialism compatible with "free enterprise and free competition."

But the current campaign has been a kind of anti-Godesberg, in the sense that the party of the left among the two natural governing parties has broken with the central tenets of Germany's postwar consensus: that modern Germany's identity is indissolubly linked to the West, and that German nationalism can find full expression within the trans-national purposes of the NATO alliance.

Today the SPD is a serious competitor for national power that it would use to frustrate the most important decision NATO has made in a generation. Doing so would have the perverse consequence of strengthening the "peace" movement by making arms control talks pointless. Why would Moscow negotiate about limits if NATO cannot consummate deployment decisions?

If Kohl wins, extra-parliamentary extremism may follow. With an impertinence that reflects its growing contempt for Western Europe, Moscow, in a German-language broadcast, has warned Germans that Kohl's election would mean social disturbances. Imagine, say, 200,000 persons occupying the sites where missiles are to be deployed beginning late this year. That is a tiny fraction of a nation of 62 million, where polls indicate a high level of affection and respect for America. But the media projection of the resulting riots and casualties would test Germany's composure and have an unpredictable effect on U.S. opinion.

Today many Europeans, and especially Germans, are preoccupied with the destructiveness of modern weapons. Thus, it is well to remember that in the Thirty Years War, Germany lost 35 percent of its population. Bohemia's population fell from 3 million to 780,000, and 30,000 of 35,000 villages were destroyed. By 1641, Wurtemberg's population had fallen from 400,000 to 48,000. This was at a time when people had to be killed one at a time, often with muscle power.

Today as then, Germany's inescapable fate is to be the cockpit of European history and never distant from danger.