So maybe our country doesn't need a foreign policy between now and Jan. 20, 2001, when President Clinton leaves office. Or maybe Senate Majority Leader Trent Lott will volunteer to travel the world and explain the intricacies of Republican caucus politics to befuddled foreign leaders.

The dispiriting thing about the Senate's rejection of the nuclear test ban treaty on Thursday is that the overwhelming majority of the Senate knew that holding the vote at all was a terrible idea. The outright rejection of the treaty undermined efforts by the United States to encourage other countries -- India and Pakistan notably -- to pause before plunging farther into the nuclear competition. It told America's closest allies in Britain, France and Germany that their views didn't matter to us. It let China and Russia score cheap points against us, and also let them off the hook on the testing issue.

"I don't know what moral suasion the U.S. has right now," Sen. John Chafee of Rhode Island, one of only four Republicans to support the treaty, said in an interview. "I don't know how we can lecture other countries to stop their testing after this has occurred. We've lost a very valuable platform."

The Senate knew this. That's why 62 senators (62 out of 100 is a majority in most mathematical and political systems), including 24 Republicans, signed a letter urging that a vote be postponed.

But 62 potential votes meant nothing because those 24 Republicans weren't quite a majority of the Republican Senate caucus. Lott himself seemed prepared to do a deal preventing this foolish vote. Instead, he gave way to Republican senators such as Jon Kyl of Arizona and James Inhofe of Oklahoma for whom only a stake through the heart of the treaty would do.

Sen. Joseph R. Biden (D-Del.) says Lott gave Democratic leaders assurances he could get the vote postponed, only to back off after Republican hard-liners read Lott the riot act. Lott, of course, denies he was pressured and pronounced killing the treaty "the right thing for our country."

Democrats also have responsibility here. They badly miscalculated in making the deal that led to this vote. The administration was slow to mobilize. "The president didn't get engaged early enough," Chafee says, while Senate Democrats, by their "taunting of Republicans," created a mood in which bipartisanship was unlikely.

Biden agrees the Democrats misplayed their hand. But he counters that many Republicans who knew better were not willing to break with their party to prevent a vote they knew should not have happened.

"I've never seen a time when so many people -- myself included -- who were for or against the treaty, in and out of government, in the foreign policy community and, yes, in the press, so underestimated the degree of partisanship and isolationist feeling that permeates the Republican Party," he said.

Of course, many genuine internationalists also opposed this treaty. But it was a Republican, Sen. Arlen Specter of Pennsylvania, who expressed alarm about the mood in his party. "There are some who just want to have Fortress America," he told the New York Times.

Many Republican opponents of the treaty were hoping to embarrass Clinton without actually having the vote. "They figured they could come back from the brink," Biden said. But they couldn't.

If anyone doubted that continuing Republican antipathy to Clinton played a role in this mess, consider Sen. Jesse Helms's dismissal of British Prime Minister Tony Blair's strong endorsement of the treaty. Recounting an imaginary conversation between Clinton and Blair, the North Carolina Republican posited that Blair ended his chat with the words: "Give Monica my regards." That's what the foreign policy of a great nation has come to.

What's wrong with this picture is not that an important and controversial treaty isn't immune from criticism in a serious debate. The problem is that the serious debate never happened. You'd think the Senate, which likes to call itself "the greatest deliberative body in the world," would have held extensive hearings -- especially with the world watching us so closely.

Nor is partisanship a problem. Most of the serious international issues in our past divided the country. Every war in this century was controversial, either before or during its prosecution.

But an intelligent partisanship that seeks to sharpen choices is different from a partisanship that thwarts debate and needlessly reduces the country's capacity to create a less dangerous world. At least 62 senators knew this. They will long regret the fact that they failed to work their will.