A MERICA'S MILITARY and economic preeminence is bound to excite jealousy: from French sneers about "hyperpower" to Russia's chip-on-the-shoulder nationalism to Malaysian bravado about the "Asian Way." Yet U.S. power is so overwhelming that no open and direct challenge can threaten it. Resentment therefore finds expression mainly in ineffectual growls and insults. Just occasionally it spills into secretive, insidious channels: into terrorism.

The past few days have brought a reminder of this unsettling logic. Articles have celebrated the close of the American Century and the dawn of what may turn out to be a second one. At the same time, law enforcement agencies have been forced to tighten security at borders and airports. Suspected terrorists have been arrested on the border between Canada and Vermont, between Canada and Seattle, and at a checkpoint for a U.S.-bound flight in the Bahamas.

Given the bombing of two U.S. embassies in Africa last year, the threat of foreign terrorism must be taken seriously. The author of those attacks, Osama bin Laden, remains active, and the Jordanian authorities recently arrested suspects believed to be part of his network. At the same time, however, excessive concern plays into the hands of the enemy. The terrorist's aim is to spread terror. To succumb to fear is to grant the terrorist a victory, whether or not anything gets blown up.

The authorities are walking this fine line between caution and capitulation. The State Department has given warning that Americans abroad may be the targets of terrorist attacks, but it has not gone so far as to advise against travel. The Justice Department has asked Americans at home to be on the lookout for suspicious packages, but it adds that it has no knowledge of any planned terrorist attack. President Clinton himself has advised citizens "to go about their holidays and enjoy themselves," but he has also urged people who "see anything suspicious to report it immediately."

It is tempting to resent these mixed messages, which disquiet citizens without offering any clear plan of action, and which serve to innoculate the government against accusations of unpreparedness in the event of a terrorist strike. But the reality--for the next few days and possibly for as long as America is an envied superpower--is that we must all learn to live with the risk of terrorism without being terrorized by it. So long as America's enemies cannot attack directly, they will be tempted to do so indirectly. The right response is to take sensible precautions and then carry on as usual.