LAST WEEK, the United States and the Soviet Union reached an "agreement in principle" to eliminate a whole class of nuclear weapons and the White House announced that Soviet leader Mikhail Gorbachev would sign a treaty in Washington this fall. Already politicians and even some of the experts who should know better have begun hailing the agreement as an historic breakthrough.

Once again, the American people will be treated to that multimedia extravaganza inevitably billed--in the manner of a professional wrestling match--as a "Superpower Summit." The leaders of the United States and the Soviet Union will take advantage of numerous photo opportunities before heading to a small cottage for a brief meeting of the minds. They'd better bring some No Doz; summits have proven to be boring, uneventful and ultimately useless.

THERE HAVE been 11 summits since September 1959, when President Eisenhower and Nikita S. Khrushchev held a Camp David chat. Since, a few summits have centered on the signing of pre-arranged agreements, which conveniently leave summiteers nothing to discuss. In 1972, for instance, Nixon and Brezhnev signed the ABM treaty and in 1979 Carter and Brezhnev agreed to SALT II. Other summits, in 1959, 1967 and 1985, have not centered on anything at all.

Summits have been, especially in the Reagan years, nothing more than public relations ploys cooked up for a domestic audience. Presidents meet their Soviet counterparts to prove that superpower relations are not as bad as critics claim. Or they go to sign treaties. But the treaties are never negotiated in person: they are the product of several months or years of hard work awaiting only the signature of two leaders--leaders who more often than not aren't capable of understanding the detail of the agreements.

BUT A summit can be something other than just a harmless "getting to know you" social event or a public signing. In 1961 Soviet leader Khrushchev left a stormy summit with Kennedy thinking the American leader was a vacillating and indecisive man. Many historians argue that this experience led Khrushchev to believe he could place missiles in Cuba without worrying about an American response. Indirectly, but yet importantly, the 1961 summit almost led to a nuclear war.

Worst of all, an American president may someday end up where Reagan almost tread last October. At the summit in Reykjavik, Iceland, Reagan almost agreed to dramatic cuts in long-range nuclear weapons in exchange for limits on American space defense plans. Regardless of whether one believes in the promise of SDI, the picture of an aging president, unfamiliar with nuclear strategy, in free-form negotiations with the Soviets is a frightening one.

FRIGHTENING because summits ultimately allow presidents and general secretaries of the Soviet Union to disrobe themselves of their foreign policy advisers. They begin to compromise and agree on matters they have very little experience or knowledge of, much like an unwary tourist in an Arab bazaar. This is particularly ominous for the United States, where the last four presidents have been a crook, a football player, a peanut farmer, and an actor. Thanks to television's role in American electoral politics, we can't expect our presidents to be experts on foreign affairs--but they're guaranteed to be both good-looking and charismatic.

In the 19th century, Europe maintained a hundred-year peace partially because the European monarchs left foreign policy up to civil servants who knew what they were doing. Men such as Castlereagh, Talleyrand, Metternich, and Bismarck maintained the Concert of Europe without excessive interference from their superiors. Today's leaders should learn from that example.