One man, one gun. That may be all that is needed to throw the long sought Mideast peace agreement off track.

The horrible massacre in Hebron last week was the act of a fanatical Israeli settler. A follower of the late Rabbi Meir Kahane, he firmly believed that the current peace negotiations were a capitulation by Israel.

His despicable act, which took the lives of at least 40 Muslim worshippers, has sparked a surge of anti-Israeli violence across the occupied territories. The massacre has also strengthened the hand of those fringe Islamic groups that have long opposed the settlement with Israel.

Rescuing the fragile peace process will be a difficult procedure. President Clinton's call for Palestinian and Israeli negotiators to meet in Washington is a positive, if unspectacular, first step. U.S. intervention has in the past borne fruit.

But the main burden will obviously fall on he parties themselves. Palestinian leaders who support the peace process will have to avoid inflaming anti-Israeli sentiment beyond expected levels.

The massacre obviously affords these leaders an opportunity to rail against Israel, and it will take a large measure of restraint to pass up the chance. Palestinian leaders must not try to use the massacre as an excuse or breaking the agreements that have been worked out with Israel.

Israel, for its part should follow through on its promise to compensate the victims and their families. The Israeli government should also review that policy of allowing settlers to keep assault weapons in their homes. In certain cases, the Israeli settlements are in enough danger that this is a prudent measure; in others it is unnecessary.

The peace process has been put in danger by the action of one fanatic. Salvaging it must be the work of many, reasonable people from all sides.