One of Sharon's final operations before leaving the army in 1952 was the semi-successful Operation Bin Nun Alef into Jordan. During the operation he suffered serious injuries, after which Sharon had recommended to the General Staff that an elite force, trained in commando tactics, be set up for reprisal operations. After a series of unsuccessful retribution infiltrations by existing IDF units, Ben Gurion pressed Chief of Staff Mordechai Maklef to establish such a special forces unit in the summer of 1953. This was Israel's first, and reservist Ariel Sharon was recalled to duty.