In 1958, the SPUSA welcomed former members of the Independent Socialist League (ISL), which before its 1956 dissolution had been led by Max Shachtman. Shachtman had developed a Marxist critique of Soviet communism as "bureaucratic collectivism", a new form of class society that was more oppressive than any form of capitalism. Shachtman's theory was similar to that of many dissidents and refugees from Communism, such as the theory of the "new class" proposed by Yugoslavian dissident Milovan Djilas. Shachtman's ISL had attracted youth like Irving Howe, Michael Harrington, Tom Kahn and Rachelle Horowitz. The Young People's Socialist League was dissolved, but the party formed a new youth group under the same name.