I think the most important historical lesson is that power tends to become corrupt. Any kind of power – powerful government or powerful nation. We see it throughout history. Those who get the power abuse it. An example of this is in Ukraine: after 1991, when the Soviet Union collapsed, some shrewd folk became very powerful by privatizing formerly federal and public land and enterprises. They abused their power and took over the government by controlling the press and media. Once in power they maintained their power by rigging the national elections and using their wealth to essentially buy their way into power. What happened in Ukraine illustrates the fact that those in power abuse it. The historical lesson learned is that power always tends to corrupt, and the people of a nation must prevent one party from getting too much power. Human history is a history of power: parties trying to control the nation, nations trying to control the world. And in any nation there usually form two sides of the political spectrum: conservatives are those who are in power and do not want to change anything, and liberals are those who are not in power and want to change everything. What we also often see in history is that a nation that grows and becomes more and more powerful tends to always collapse. Examples include the Roman empire, Russian empire, Ottoman empire, etc.