he beginning of the Metapolitefsi era. On 14 August 1974 Greek forces withdrew from the integrated military structure of NATO in protest at the Turkish occupation of northern Cyprus. The first multiparty elections since 1964 were held on the first anniversary of the Polytechnic uprising. A democratic and republican constitution was promulgated on 11 June 1975 following a referendum which chose to not restore the monarchy.
Meanwhile, Andreas Papandreou founded the Panhellenic Socialist Movement (PASOK) in response to Karamanlis's conservative New Democracy party, with the two political formations alternating in government ever since. Greece rejoined NATO in 1980. Traditionally strained relations with neighbouring Turkey improved when successive earthquakes hit both nations in 1999, leading to the lifting of the Greek veto against Turkey's bid for EU membership.
Greece became the tenth member of the European Communities (subsequently subsumed by the European Union) on 1 January 1981, ushering in a period of remarkable and sustained economic growth. Widespread investments in industrial enterprises and heavy infrastructure, as well as funds from the European Union and growing revenues from tourism, shipping and a fast-growing service sector have raised the country's standard of living to unprecedented levels. The country adopted the euro in 2001 and successfully hosted the 2004 Summer Olympic Games in Athens.
More recently, Greece has been hit hard by the late-2000s recession and central to the related European sovereign debt crisis. The Greek government debt crisis, subsequent economic crisis and resultant, sometimes violent protests have roiled domestic politics and have regularly threatened both European and world financial market stability in since the crisis began in 2010