A lot of cajoling by US President Roosevelt and the fact that Germany declared war on the US and started torpedoing US shipping near the US eastern coast.
The Americans helped the Allies by sending resources to them during WWI.
The US and the Allies won the war and the US gained control of the Philippines, causing it to become a world power.
the Germans' use of unrestricted submarine warfare
UK, USSR, and France
Cultaral ties to Britain (traded with Britain and Allies more than the Central Powers) Germany's use of unrestricted submarine warfare Germany's Zimmerman Note to Mexico
The general plan for the invasion of Europe by the allies.
Because the Allies were on the opposing side; the Allies didn't agree with what was happening in Europe. America only joined the Allies after Pearl Harbor, which was caused by Japan. Japan was a member of the Axis, and thus an ally of Germany. The Allies (especially Britain, during the Battle of Britain), proved that they weren't going to let Hitler achieve his plans.
The Battle of the Bulge.
they befriended the negus.
They had a treaty which obligated them to help their allies, France and Russia, and they decided to honour it. They were also fearful of Germany and thought it to be a threat to their own naval development in Europe.
The Germans believed the ships were carrying war supplies to the Allies.
General Dwight D. Eisenhower was the Supreme Leader of the Allied Forces in Europe.
lend lease.
World War caused Europe to divide. By Omar Adam
I think Belgium have more to do with The Netherlands and Luxembourg (the BENELUX countries) but I also think that during World War 2 the whole of Europe became allies. Except for Germany and Italy of course.
the allies occupied Germany.
Norway's allies were Britain, and the allies including the U.S.