Hitler declared to attack the Soviet union after

the signing of the Molotov-Ribbentrop Pact between Germany and the Soviet Union, which was a non-aggression treaty. The pact was signed on August 23, 1939, and Hitler saw it as a strategic move to secure the Eastern front while focusing on his expansion plans in Western Europe. However, the pact was ultimately a temporary measure, as Hitler never intended to fully adhere to it.

After successfully conquering Western Europe, Hitler turned his attention towards the Soviet Union and began preparing for an invasion. Operation Barbarossa, as it was known, was launched on June 22, 1941. Hitler believed that the Soviet Union could be conquered quickly, underestimating their resilience and military capabilities.

The invasion of the Soviet Union marked a major turning point in World War II and resulted in a long and brutal conflict between the two powers. Despite initial successes, the German army faced numerous challenges, including harsh weather conditions, vast Soviet territory, and the Soviet Union's determination to defend their homeland. Ultimately, Hitler's decision to attack the Soviet Union led to the downfall of Nazi Germany.

Here is a step-by-step timeline leading up to Hitler's decision to attack the Soviet Union:

1. Non-Aggression Pact with the Soviet Union: On August 23, 1939, Germany and the Soviet Union signed the Molotov-Ribbentrop Pact, a non-aggression agreement that also included secret protocols to divide Eastern Europe into German and Soviet spheres of influence.

2. Invasion of Poland: On September 1, 1939, Germany launched an invasion of Poland, marking the beginning of World War II. The Soviet Union attacked Poland from the east a few weeks later on September 17, 1939.

3. Occupation of Western Europe: Over the next year, Germany successfully conquered several Western European countries, including Denmark, Norway, the Netherlands, Belgium, and France.

4. Failed Invasion of Britain: In the summer of 1940, Hitler ordered the Luftwaffe (German Air Force) to launch an air campaign against Britain, known as the Battle of Britain. Despite significant damage to British cities, the Royal Air Force successfully defended the country, and Hitler was unable to achieve air superiority or invade Britain.

5. Balkan Campaign: In early 1941, Germany, along with its allies Italy, Hungary, and Bulgaria, launched a military campaign in the Balkans, targeting Yugoslavia and Greece. The campaign was successful, with Axis forces quickly defeating the countries in the region.

6. Operation Barbarossa: On June 22, 1941, Hitler launched Operation Barbarossa, which was the code name for the invasion of the Soviet Union. The invasion involved over 3 million German troops and was aimed at gaining control over vast territories and resources in the east.

It is important to note that Hitler's decision to attack the Soviet Union came from his expansionist goals and perceived ideological differences. He believed that by defeating the Soviet Union, Germany could acquire Lebensraum (living space) and eradicate what he considered to be the threat of communism.