Answer:
There are various social, economic, and political reasons for the rise of imperialism in Europe. Trade has provided huge profit for the European states and there were greater zeal to protect it. The British occupation of Egypt was one such occupation to control the Suez canal. Another reason was the belief in the superiority of European race supplemented by social Darwinism. the competition among the European nations was not only economic reasons but it was also a matter of national prestige.
The U.S. withdraws from the war. Because they lost the support of the American people thinking that the war was unnecessary
This is your opinion if they we're aggressive. of course When the United States sends a naval delegation, led by Commodore Matthew Perry, to "open" Japanese ports in 1853, the Japanese are well aware of the "Unequal Treaties" that have been imposed upon China in the previous ten years (since the Opium War of 1839-42) as a result of the superior military power of the Western nations. The Japanese respond to the challenge of the West.
So, were they aggressive when it came to their efforts?
New imperialism was focused on trade, land acquisition, and conversion (faith, language, etc.) of the african subcontinent
The Mexican army attacked them. The main cause of the war was the westward expansion of the United States. All through the 19th century Americans believed it was their right to expand westward
