At this time colonies were viewed as a major factor in determining a nations power internationally and also an engine for economic growth in a mercantilist system. Therefore, arguments in favor of U.S. Imperialism would have been fueled by the power struggle with European nations to exert global influence and dominance. Another major factor that individuals would have argued for was that colonies would have provided new markets and sources for raw materials for the growing US economy. In the end the U.S. did not become a major imperial power which most likely served the nation's power and reputation in the long run.
Answer: Fifty five percent of the land in Africa is unsuitable for any kind of agriculture except nomadic grazing. ... About 16% of the land has soils of high quality and about 13% has soils of medium quality.
China was itself an established empire and could not be conquered the same way as they did Africa and India.
What you are saying is basically equal to saying why not land in England (during that period) and turn everyone into slaves.
Since that is impossible, establishing spheres of influence allows major powers to break China from the inside.
The major powers of europe, Japan, and America ganging up on china during those days is the main reason behind China's firm foreign policy today.
