Yugoslavia, joined the UN as an original member on 24 October 1945. It was not a part of the Warsaw Pact but pursued its own version of "Communism" under Marshal Josip Broz Tito. It was a multi-ethnic state which Tito was able to maintain through a doctrine of "Brotherhood and unity", but tensions between ethnicities began to escalate with the so-called Croatian Spring of 1970–71, a movement for greater Croatian autonomy, which was suppressed. In 1974 there followed constitutional changes, and the 1974 Yugoslav Constitution devolved some of the federal powers to the constituent republics and provinces. After Tito's death in 1980 ethnic tensions grew, first in Albanian-majority SAP Kosovo with the 1981 protests in Kosovo. In the late 1980s Serbian leader Slobodan Milošević used the Kosovo crisis to stoke up Serb nationalism and attempt to consolidate and dominate the country, which alienated the other ethnic groups.