Kepler did multiple things, but his most famous work is demonstrating that the planets move in an elliptical (kind of like an oval) orbit around the sun instead of a circular orbit.
Nationalism and imperialism were major factors to the world war 1. that lead to some conflicts between nations. imperialism also contributed to start world war 1 because the European nations attacking and conquering different areas of Africa and Euro nations attacking other Euro nations for African Territory.
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?
The Roman idea of Citizenship facilitated political stability through Roman territories by "uniting" it's conquered people, since many of these people were treated with a relatively large amount of respect and were given rights that they appreciated.
