The Baltics were recaptured by invasion after the Molotov–Ribbentrop Pact (popularly known as the Stalin–Hitler Pact) of August 23, 1939, in which Stalin and Hitler divided Poland into spheres of influence. Hitler's invasion of Poland was the immediate cause of WW II. The Baltics considered Stalin's invasion and therefore his acquisition of their countries illegal and invalid acts. On March 11, 1990, Lithuania redeclared independence, Latvia on August 21, 1991, and Estonia on August 20, 1991. Russian troops still occupied the countries. The Russians owned much of the industrial capacities. There was some Russian resistance to their departure, but Gorbachev was obliged to follow his policies. In 1991 the Russians abroad were left hanging without authorization, as their current country had not stationed them there. It was to be years before national partitions were complete, during which Russians and Americans coexisted in the same countries.