The years of 1942-1943 saw World War II in it's full swing all over the world with active Eastern and Western theaters of war.
In North Africa, the allied forces of the United States, Britain and other Commonwealth nations were able to gain complete control of the region due to the following sequence of events:
1. The Allies won two wars of Coral Seas and Midway due to the power of advanced aircraft carriers.
2. The allied army was able to trap and surround Rommel's Army, further giving the an advantage
3. Eventually Rommel's army surrendered, providing the Allies complete Supremacy.