A Cease-Fire in Bosnia

WE will begin to know tomorrow just how believable the peace agreement on Bosnia worked out by former President Carter will be. That is when the Bosnian Serb forces of Radovan Karadzic and Gen. Ratko Mladic have agreed to honor a general cease-fire.

The fact that the Serbs wanted Mr. Carter to negotiate an agreement indicates they are very concerned about their prospects, at least in the immediate future. But any Balkans peace deal should invite wise caution on the part of the international community, who in the past have been too eager to accept a temporary peace that they find later to be disastrous both for the war's victims - the Bosnians - and for their own credibility.

The key to most of what the Bosnian Serbs attempt is to be found in Belgrade, with Serbian president Slobodan Milosevic. Mr. Milosevic is playing a long-term game that involves the Russians and his own design for a Greater Serbia. He may want his partner Mr. Karadzic to accept the ``contact group'' plan - set forth by Britain, France, Germany, Russia, and the United States - which gives the Serbs 49 percent of Bosnia.

Carter's trip may serve well the purposes of Milosevic. Relations between Milosevic and Karadzic have been strained. Milosevic can see that the Bosnian Serbs are becoming a liability for him. They have taken 70 percent of Bosnia, yet the war continues. No matter what the contact group's plan says on paper, it is unlikely that these great powers will force Serb troops to roll back their positions in Bosnia to the group's map. In a sense, Milosevic is saying to Karadzic: Accept your victory. The international community is not going to make you live up to any plan on paper. They have not before, and they will not now.

If the Bosnian Serbs honor the cease-fire, the West must become more pro-active than ever. It must not allow this opening toward peace to be wasted. NATO should guarantee the security of the city of Sarajevo and its resupply. Karadzic must not be allowed to use this peace as a chance to rest and resupply his forces so that the mayhem in the Balkans can resume.

The peace should not be used as a means to cover war crimes or renege on the right of people to return to their homes. The Serbs must not be allowed, as they have been in the past, to negotiate in Geneva while causing destruction in the Balkans. The Bosnian government must be allowed to purchase weapons for self-defense, as can any other recognized member of the United Nations.

The Serbs in Belgrade and Pale want Carter and the West to play their game. But with resolve, perhaps that game can be turned around.