Palestinian officials had hoped that pressure by Arab nations on the Bush administration would prompt it to restrain Israel.

Already, in anticipation of a possible war on Iraq, the Bush administration has been working to restrain Israel on two fronts.

The Bush administration may find it necessary to try to restrain Israel from pursuing Al Qaeda internationally, should that organization prove the culprit in Thursday's attacks.

The United States was unable to restrain Israel even when it felt it was necessary to do so against Syria in June 1967 and against Lebanon in 1982.

In a letter to President Bush today, 89 senators urged him not to restrain Israel from retaliating fully against Palestinian violence and to express his solidarity publicly with Israel soon.

The Bush administration's push for strong action against Iraq is running up against Arab perceptions that the United States has not done enough to restrain Israel.

He accused the United States of restraining Israel from using its full might to defeat Palestinian terrorism.

In Beirut, Lebanon's foreign minister, Jean Obeid, said "the situation is taking a dangerous course," and he called on the United Nations to restrain Israel, news agencies reported.

To Israelis, however, any American effort to restrain Israel only denies the Americans themselves the kind of stick that could compel Mr. Arafat to really move forward on negotiations.

Iraq targeted Israel with missiles during the 1991 Persian Gulf war, and only strong American pressure restrained Israel from a major air retaliation.