By the late 1930s, the situation near the USSR's borders was alarming. In 1938 and 1939, in the Far East, armed conflicts with Japan happened. Europe faced the danger of a new World War. In 1939, Stalin changed sharply Russian policy's orientation, abstaining from cooperation with democratic Western regimes and concluding a treaty with Hitler's Germany. Secured from the war on two fronts, Hitler annexed Poland and began a war with France and England. The USSR occupied the Eastern lands of defeated Poland. The other result of Soviet-German treaty was the annexation the Baltic countries, Bessarabia and Northern Bukovina by the USSR. The attempt to dominate Finland faced stubborn resistance. Only after heavy casualties did Soviet troops succeeded in inclining Finland toward a peace treaty; according to it, the USSR got Vyborg and a part of the Karelian Isthmus. Hitler's troops were annexing countries one after another while the USSR kept out of the war.
On June 22, 1941, Hitler's Germany attacked the USSR. The Red Army had lost many commanders and generals in the purges of the 1930s. In spite of many warnings and intelligence, Stalin did not expect the attack and forbade preparations because he feared provocation. As a result, during the very first hours of the war, the USSR lost most of its aviation and tanks. German troops advanced swiftly. Millions of soldiers and commanders of the Red Army found themselves surrounded or imprisoned. The enemy captured a great deal of arms and ammunition. By autumn, all of the Baltic countries, Ukraine, Byelorussia and some regions of the Russian Federation were controlled by the Germans. Most defense industrial enterprises were either taken by the enemy or evacuated to the East. The front neared Moscow. The end of the Soviet Union seemed inevitable. Stalin was already considering negotiations with Hitler and was ready to give up substantial territory.
The war caused a great upsurge of patriotism. Millions of Soviet men sacrificed their lives on the front. New armies and groups of armies were formed and vigorous and gifted generals headed them.. Guerrilla war began in the German rear. Massive aid from the US in the Lend-Lease program provided the Red Army with arms, ammunition, transport and provision. At the expense of heavy casualties, the Red Army managed to stop the German attack on Moscow in the winter of 1941-1942. In 1942, the German Army moved on the Caucasus and the Volga. However, by that time, the balance of forces had changed. The Soviet Army got new arms and developed its organization. At Stalingrad, it surrounded and destroyed the 6th German Army. The war had reached a turning point. Soviet troops advanced to the West, overcoming stubborn enemy resistance.
After victory at the Kursk Bulge, during 1943-1944, the Soviet Army liberated most of the territory of the USSR. In June, 1944, a second front was opened in the West. The spring of 1945 became the spring of Victory. Soviet troops occupied Berlin. Germany capitulated. Eastern European countries found themselves occupied by Soviet troops; pro-Soviet "people's democracy" was established. In September, 1945, in the Far East, Japan was defeated and the USSR annexed Southern Sakhalin and the Kuril Islands and Soviet troops occupied Northern Korea. A civil war took place in China; as a result, in 1949, Communists took power there. Surrounded by satellites, in fact, the USSR became the center of a global Communist empire. Only Yugoslavia, although it was under Communist rule, dared to reject Soviet influence. To protect themselves from Soviet aggression, Western European countries and the US created the military and political NATO block. The world was divided into two hostile camps.
In the years of the war, the Party's ideologists tried to take advantage of the patriotic upsurge; they relied on ethnic traditions, turned away from the propaganda of Internationalism, and appealed to Russian patriotism. In 1943, the Komintern was dissolved. People's Commissariats were renamed Ministries, All-Russia's Central Executive Committee became the Supreme Soviet. New ranks were established to recall the past of the Russian Empire. Military men put on shoulder-boards. A new national anthem spoke of "Great Rus". During celebrations dedicated to the Victory over Germany, Stalin toasted the "great Russian people" which propaganda began to call "the elder brother". The expectations of other ethnic groups encountered persecution and oppression. The struggle against any "manifestation of nationalism" increased especially after the war. Some nationalities were accused of collaboration with the Nazis and deported completely. Soviet Power turned away from proletarian Internationalism in favor of nationalist socialism, according to which all the nationalities of the multi-ethnic country were listed in a strict hierarchic order.
The West could only oppose nuclear weapon to the USSR and its satellites. The US had them, and the USSR did not. So the USSR dedicated all of Soviet science and technology and all state resources to the production of an atomic bomb. L.P. Beria supervised the project. For this reason, most distinguished physicists found themselves protected from arrest and vengeful critics. In 1949, the USSR became a nuclear state. An H-bomb program was developed as well. Simultaneously, the Communists undertook a powerful pacifist campaign in Western countries. The noble idea of prohibiting weapons of mass destruction objectively aided Stalin's aggressive plans. To probe the forces of the enemy, he began the war in Korea. The constant danger of a new World War helped to maintain the atmosphere of a besieged fortress among the Soviet people.
In first post-war years, the USSR was gripped by the euphoria of victory. New products (the watches, the cars) were called "Pobeda" ("Victory"). Millions of families received captured gramophones, watches, and clothes. And what a soldier could bring in a rucksack, a general could bring in many cars. But most of people wore out their soldier's shirts and greatcoats and lacked essentials. Members of collective farms suffered from hunger, as they got neither bread nor money for their work-days (official units of payments on collective farms). Many disabled soldiers could be seen at markets. In the cities, criminal gangs raged. The situation improved a bit after rationing was cancelled in 1947. Before each New Year, the government announced a decrease in prices. However, foodstuffs got cheaper by kopecks while other consumer goods got more expensive by rubles.
Just after the war, hundreds of thousands of former prisoners of war were indiscriminately accused of treason and repressed. Those who were unlucky enough to have been under German occupation lost their civil rights. The ideological campaigns of unmasking a "lack of ideals" in the arts and of struggling against "cringing before the West" eradicated the free thought that had awoken in the Soviet people during the war. In 1948-1949, a new wave of mass terror swept over the country. The restoration of the national economy after the war and the "Great construction projects" (such as the Volga-Don Channel) depended substantially on the slave labor of prisoners. At the same time, in Moscow, high-rises were constructed that would become a symbol of the Soviet Empire. In 1947, the 800th anniversary of the capital was celebrated with great pomp; two years later, Stalin's 70th anniversary was celebrated. In 1952, the aging Kremlin leader prepared new wave of terror and planned to purge his closest retainers. His death (on March 5, 1953, according to official information) prevented him from implementing those plans.