Following the disastrous Six-Day War of 1967, Egypt waged a War of Attrition in the Suez Canal zone. In 1971, four years into this war, Sadat endorsed in a letter the peace proposals of UN negotiator Gunnar Jarring which seemed to lead to a full peace with Israel on the basis of Israel's withdrawal to its pre-war borders. This peace initiative failed as neither Israel nor the United States of America accepted the terms as discussed then.