Yasser Arafat is in trouble - or so he wants U.S. President George Bush to believe. He sent a telegram to Bush this morning, telling him that the situation in the Palestinian Authority \"is on the verge of explosion, and that it could threaten the entire Middle East.\" Arafat asked that Bush intervene quickly against what he calls the \"dangerous Israeli escalation.\" Bush said again last night that Israel has the right to defend itself.