The Olympics were disrupted by another, even larger boycott, this one led by U.S. president Jimmy Carter, part of a package of actions to protest the December 1979 Soviet invasion of Afghanistan. Carter engaged in extensive arm-twisting to gain support from other nations. Some governments, like those of Great Britain and Australia, supported the boycott but allowed the athletes to decide for themselves whether to go to Moscow. No such freedom of choice was allowed U.S. athletes, as Carter threatened to revoke the passport of any athlete who tried to travel to the USSR. In the end, 65 nations turned down their invitations to the Olympics; probably 45 to 50 did so because of the U.S.-led boycott. Eighty nations did participate - the lowest number since 1956.