Final answer:
In World War II, American military began with North Africa invasion to strike at less defended Southern Europe, distract Axis powers and prepare for future invasions.
Step-by-step explanation:
The American military actions in Europe during World War II began with an invasion of North Africa primarily because it allowed the Allied forces to strike at a less defended Southern Europe, which is Option 4. This strategy, known as Operation Torch, was designed to help open up a second front against the Axis powers to divert their resources and attention, thereby weakening their defences in northern Europe. Moreover, control of North Africa would provide the Allied forces with a launching pad for future invasions into Southern Europe, including Italy, thus putting additional pressure on Germany.
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