Yes - on 1 September 1939
With the invasion of Poland in 1939.
The invasion of Poland by Germany in Europe in 1939 caused the start of World War II. It was the line drawn in the sand.
World War 2, with his invasion of Poland on September 1, 1939.
Hitler's invasion of Poland
WW2 began with the invasion of Poland by Hitler in 1939, so they didn't "enter" the war. They were the start of the war.
Poland
It began with the German invasion of Poland.
World War 2 started with the German invasion of Poland on September 1st, 1939.
World War 2 started with the German invasion of Poland on September 1st, 1939.
Because on the other side of Poland was the Russian provinces and Hitler did not have the supplies to start a war with Russia.
The 1939 invasion of Poland caused Britain to declare war on Germany, which started WWII.
I believe it's Blitzkrieg.