Nazi Germany was never close to winning WW2. Because nobody can take on the World and survive, let alone win.
One look at the sheer number of Allied Powers that Germany faced in WW2 is clear proof how delusional the Nazis truly were:
Dates on which states joined the Allies:
Following the German invasion of Poland:
Poland: September 1, 1939
United Kingdom: September 3, 1939
France: September 3, 1939
Australia: September 3, 1939
New Zealand: September 3, 1939
Nepal: September 4, 1939
Newfoundland: September 4, 1939
Tonga: September 4, 1939
South Africa: September 6, 1939
Canada: September 10, 1939
After the end of the Phony War:
Denmark: April 9, 1940
Norway: April 9, 1940
Belgium: May 10, 1940
Luxembourg: May 10, 1940
Netherlands: May 10, 1940
Malta: June 10, 1940
Free France: June 18, 1940
Greece: October 28, 1940
Kingdom of Yugoslavia: April 6, 1941
Soviet Union: June 22, 1941
Tannu Tuva: June 25, 1941
After the attack on Pearl Harbor:
Panama: December 7, 1941
Philippines: December 7, 1941
Costa Rica: December 8, 1941
Dominican Republic: December 8, 1941
El Salvador: December 8, 1941
Haiti: December 8, 1941
Honduras: December 8, 1941
Nicaragua: December 8, 1941
United States: December 8, 1941
Republic of China: December 9, 1941
Guatemala: December 9, 1941
Cuba: December 9, 1941
Provisional Government of the Republic of Korea (government in exile): December 9, 1941
Czechoslovakia (government in exile): December 16, 1941
Mexico: May 22, 1942
Brazil: August 22, 1942
Ethiopia: December 14, 1942
Iraq: January 17, 1943
Bolivia: April 7, 1943
Iran: September 9, 1943
Italy: October 13, 1943 (formerly a member of the Axis)
Colombia: November 26, 1943
Liberia: January 27, 1944
After D-Day:
Romania: August 25, 1944, (formerly a member of the Axis)
Bulgaria: September 8, 1944, (formerly a member of the Axis)
San Marino: September 21, 1944
Albania: October 26, 1944
Hungary: January 20, 1945, (formerly a member of the Axis)
Bahawalpur: February 2, 1945
Ecuador: February 2, 1945
Paraguay: February 7, 1945
Peru: February 12, 1945
Uruguay: February 15, 1945
Venezuela: February 15, 1945
Turkey: February 23, 1945
Lebanon: February 27, 1945
Saudi Arabia: March 1945
Argentina: March 27, 1945
Chile: April 11, 1945
People's Republic of Mongolia: August 9, 1945
Link - http://www.newworldencyclopedia.org/entry/Allied_Powers_(World_War_II)
Germany was never close to defeating all of those Allied Powers to win the war.
Which just goes to show how truly damn stupid the Nazis were for believing their own propaganda & thinking they ever could.