iroquois league: a league of Iroquois tribes including originally the Mohawk, Oneida, Onondaga, Cayuga and Seneca (the Five Nations); after 1722 they were joined by the Tuscarora (the Six Nations)
league: an association of states or organizations or individuals for common action
first strike: the initial use of nuclear weapons to attack a country that also has nuclear weapons; considered feasible only when the attacker can destroy the other country's ability to retaliate