Albania declared its independence from the Ottoman Empire in 1912, but was conquered by Italy in 1939 and occupied by Germany in 1943. Communist partisans took over the country in 1944. Albania allied itself first with the USSR (until 1960), and then with China (to 1978). In the early 1990s, Albania ended 46 years of isolated communist rule and established a multiparty democracy. The transition has proven challenging as successive governments have tried to deal with high unemployment, widespread corruption, dilapidated infrastructure, powerful organized crime networks, and combative political opponents. Albania has made progress in its democratic development since it first held multiparty elections in 1991, but deficiencies remain. Most of Albania's post-communist elections were marred by claims of electoral fraud; however, international observers judged elections to be largely free and fair since the restoration of political stability following the collapse of pyramid schemes in 1997. Albania joined NATO in April 2009 and in June 2014 became an EU candidate. Albania in April 2017 received a European Commission recommendation to open EU accession negotiations following the passage of historic EU-mandated justice reforms in 2016. Although Albania's economy continues to grow, it has slowed, and the country is still one of the poorest in Europe. A large informal economy and a weak energy and transportation infrastructure remain obstacles.