Work has been furious on all sides of the peace equation in recent weeks, but the only certainty to emerge is that it is easier to destroy the peace effort than to seal an agreement. Tit-for-tat killings and terrorist bombings have dimmed even the most optimistic hopes that a solution could be confirmed before President Clinton leaves office January 20. Beyond that date there is little hope, especially with hardliner Ariel Sharon leading Israeli Prime Minister Ehud Barak by a substantial margin in polls just weeks before the Feb. 6 election. Travel to the region remains risky, with little certainty about what level of violence could occur or where it might happen.