DIED. Janos Kadar, 77, leader of Hungary who invited the Soviet tanks that crushed the 1956 uprising; in Budapest. In power from 1956 until forced out in May 1988, Kadar outlasted five regimes in Moscow by toeing the Soviet line on foreign affairs. At the same time, he ushered in domestic reforms that blended socialism with free-market principles. The resultant "goulash Communism" produced enough economic vitality to make Hungary the envy of the Soviet bloc.