11.   Israel vowed a swift response and officials suggested the mission of Anthony Zinni, the American mediator working to negotiate a cease-fire here, had been severely undermined.

12.   Israeli and Palestinian negotiators will meet separately with American mediators today, and there may be three-way meetings if progress is made.

13.   It is by no means clear that the diplomatic acrobatics of the chief American mediator, Richard Holbrooke, can resolve it.

14.   It was the fourth suicide bombing in the two weeks since the arrival of the American mediator, Gen. Anthony C. Zinni.

15.   Negotiators for both sides are now meeting with American mediators in Washington.

16.   Now the bargaining positions of the two sides have slipped so far apart that Dennis Ross, the American mediator, is thinking about coming home.

17.   Richard Holbrooke, the chief American mediator, understands this need for strong measures.

18.   Senior officials from both sides are in Washington, talking to American mediators, probably to each other as well.

19.   Some Palestinians fear that Israeli officials and American mediators will be distracted and that their peace track will be relegated to second-class status.

20.   Still, American mediators believed that it was probably irreversible and would eventually achieve its goal of two neighboring states.