Beginning of World War II (1 September, 1939 - 22 June 1941)
On September 1, 1939, at sunrise, troops of German Vermacht, out of the blue, began military actions against Poland. Using overwhelming dominance in manpower and technique, Nazi commanders could manage to gain large-scale results for a very short time. In spite of the fact, that France, Great Britain and countries of the British Commonwealth declared war to Germany right away, these countries didn't render Poland a real and effective assistance. Courageous resistance of Polish warriors in suburbs of Mlava and close to Modlin and heroic 20-day defence of Warsaw couldn't save Poland from collapse.
At the same time (within 17-29 September) units of the Soviet Army troops practically with no resistance occupied close-to-border regions of Belorussia and the Western Ukraine. By 28 September, 1939 the first campaign of the war had been over. Poland no longer existed.
That very day in Moscow a new Soviet-German Treaty "About friendship and the border" was signed, which confirmed the division of Poland. New secret covenants gave the USSR a possibility of "freedom of action" in creation of "security sphere" in the USSR's Western borders, confirmed attachment of Western regions of Belorussia and the Ukraine, allowed the USSR to complete agreement about "mutual aid" with Estonia on 28 September, 1939, with Latvia on October 5, with Lithuania on October 10. According to those agreements the USSR received a right to station its troops in the above lands and to set up military air-bases and naval stations there as well. Stalin gave out hundreds of antifascists to Gestapo, who had been in hiding from Nazi in Russia, and also carried out deportation of hundreds thousands of the Poles (not only former military men but civilian population as well)
At the same time Stalin's administration strengthened its pressing onto Finland. On October 12, 1939 Finland was suggested to complete a treaty on "mutual aid", but the latter refused, and the negotiations weren't a success.
Poland's frustration, Germany's temporary union with Stalin allowed Hitler to enjoy the sound rear for carrying out a "blitzkrieg" on the West-European theatre of operations. Already on October 12, 1939 Hitler signed a directive about preparation for an attack to France, and in ten days after that he issued a plan of strategic concentration of German troops for carrying out offensive operations against the West.
Soviet leadership undertook active steps to broaden "sphere of safety" in the North-West. On November 28, 1939 the USSR, in unilateral way, denounced the treaty with Finland on non-offence and started military operations (which lasted almost three months) against the country. The following day in a place of Ternoky "The Government of Democratic Finnish republic" was hurriedly declared.
On 12 March 1940 a peace treaty between Finland and the USSR was signed in Moscow, taking into consideration territorial demands towards the USSR. The Soviet Union suffered enormous loss in the war: 127,000 perished or missing; 248,000 wounded and frost-bitten. Finland's loss was 48,000 perished and 43,000 wounded.
In political terms the war brought much harm to the Soviet Union. On 14 December, 1939 League of Nations Council accepted a resolution to expel the USSR from the lists of the foundation, disapproved the USSR's steps, directed against Finland, and called the member-states of the League to support Finland. The USSR happened to be in international segregation.
The results of the "Winter War" obviously showed weakness of "adamantine" Soviet Armed Forces. Soon after Minister for Defence K. Voroshilov was replaced with S. Timoshenko.
In spring of 1940 Vermaht troops began a large-scale military operation in Western Europe. On 9 April, 1940 a striking group of Hitler's units (about 140,000 of manpower, 1,000 aircrafts and all Naval forces) attacked the Netherlands and Norway. The Netherlands, that had only 13,000 Army, was occupied for a few hours, and the government announced about capitulation right away.
The situation in Norway was a little different. The Armed Forces there could manage to escape frustration and drew off into the depth of the country. British and French forces came to help them. The armed fight promised to become a rather lengthy one, so already on 10 May, 1940 Hitler started an offensive, named "Helb"; according to that it was supposed to make a lightning-like drive at France via Luxembourg, Belgium and Netherlands, bypassing French defence line "Magino". On 22 June 1940 France's Capitulation Act was signed, according to which its northern territory was occupied by Germany, and the Southern part remained under the control of "collaboration" government of Marshall Peten (the so-called "Pishi" regime).
The defeat of France caused a sharp change in strategic situation in Europe. There appeared a real threat of German invasion into Great Britain. A large-scale marine war was in progress on naval communications, where German submarines sank 100-150 trade vessels per month.
Already since summer of 1940 the front in the West no longer existed, and the would-be collision between Germany and the USSR had more and more tangible lineament.
As a result of German "policy of pacification" territories with 14,000,000 population on the Northeast and East of Europe were adjoined to the USSR, and the Western border was pushed 200-600 km. aside. On the VIII Session of the USSR Supreme Soviet (2-6 August 1940) those territorial acquisitions were legally drawn up by means of laws about republics of Moldavia, Latvia, Estonia and Lithuania formation.
Germany, after its victory over France, activated preparations for war against the USSR. The question about "the westward campaign" was discussed on 21 July 1940 on Hitler's meeting with commanders of different combat arms, and on 31 July he set a task to begin the operation in May 1940, and to fulfil it in 5 months.
On August 9, 1940 the decision about moving the Vermaht forces to the USSR borders was accepted, and since September the troops started to concentrate in Romania. Simultaneously a vast desinformation campaign against the USSR administration began, that played a very harmful for the USSR role at the beginning of the war. On September 27 Germany, Italy and Japan signed the Tripartite Pact, with which Hungary, Romania, Slovakia, Bulgaria and Croatia affiliated later. And on 18 December 1940 Hitler affirmed famous "Barbarossa Variant" - plan of the war against the USSR.
With an eye to conceal war preparations I.Ribbentrop offered I.Stalin (13 October, 1940) to take part in dividing spheres of interest world-widely. The meeting on this question was held on 12-13 November, but it came to no result, because of inadmissible conditions from both sides.