At various times, he has been a leader in getting the PLO, and later the Palestinian Authority, to recognize the existence of the State of Israel; at other times he has publicly stated that the peace treaty with Israel is a temporary measure only, and that Islamic law provides precedence for revoking it.
In 1996, he gets the peace Nobel Prize (with [Shimon Peres]? and [Yitzhak Rabin]?).