The Egyptians sought to exploit this Israeli belief to their advantage. Ever since assuming office, Sadat had continually threatened Israel with war, engaging in brinkmanship, until his threats became ignored by Israel and the world. In order to position their forces for the attack against Israel, the Egyptians announced an exercise by the canal. Exercises had been conducted numerous times before, and in May and August 1973 false alarms had caused the Israeli army to mobilise in response to these exercises, costing Israel some $10 million on each occasion. This time, when the Egyptians began exercises on October 1 to last until October 7, Aman disregarded the heightened military activity as training maneuvers. Troop movements on the Syrian front were detected as well, but Aman concluded that the Syrians would not go to war without the Egyptians.