Why did hitler most likely believe germany had a right to invade other countries?

the treaty of versailles did not state that germany could not invade other countries.
the german economy relied on selling exports, and these nations were no longer purchasing them.
the third reich was a struggling government that needed to gain land.
the concept of nationalism meant keeping all germans together.

Hitler believed that Germany had a right to invade other countries because the concept of nationalism meant keeping all Germans together.

Explanation:

Adolf Hitler was an Austrian-born German politician and the leader of the Nazi Party. He was Reich Chancellor of Germany from January 30, 1933 until his death and Head of State from August 2, 1934 also until his death.  

Hitler turned Germany from a budding democracy, the Weimar Republic, into a totalitarian state with himself as the absolute dictator, brutally crushing any opposition to his regime. Opponents were imprisoned in concentration camps or murdered. From the beginning, Hitler's policy was based on the use of force and terror through the SA and the SS. Hitler's endeavors to undo the humiliations of the Treaty of Versailles (1919) for Germany and his expansion policy to create Lebensraum for Germany, based on the idea of the unification of all germanic nations, led to the beginning of World War II. Another characteristic of Hitler's politics was his extreme racist Nazi ideology. This led to the systematic extermination of millions considered untermenschen, such as Jews, but also Slavic peoples, gypsies, disabled people and other non-Jewish victims of the Nazi regime, in the Holocaust. When it was clear that Germany was losing the war, Hitler ordered the German people to fight to the bitter end and that the Nazis destroy German industrial complexes. He killed himself in his underground bunker in Berlin. At the end of his reign, Germany and much of Europe were in ruins and tens of millions died.