Should the U.S. be the world's police?

We don't learn the real truths about history, in school. We learn facts and events in an abstract manner. We learn the reasons for particular events that have changed history but we don't learn the contact of the cumulative effect. Europe has a history of individual countries building up their armies for over 1000 years and fighting each other to gain lands, sea ports and gold. Europe has even fought over drugs through the spice trade, which was really Opium from China and Middle East Countries. America tried really hard to stay neutral since its Independence from England. France tried no more than 7years after American independence to pull America into another war with Britain. America was victimized by both sides for not helping either side. This example is a microcosm of Europe over the last 1000 years. Countries were constantly fighting over the same land pulling other courtiers into their conflicts. Sometimes a European country would invade a neutral country just to invade another country. The mentality of war in Europe was win a war and you get land, gold and prestige and lose a war and you have to give up land, gold and prestige. This was the excepted European war mode. This model allowed defeated countries to retreat and then rise again in another 15-20 years. There was no real concern from the ruling class since their personal wealth and land was never really at risk. We call Hitler the mad man but the untold reality of past European dictators and conquers is there was a multitude of crazy men that tried to conquer all of Europe from the Roman Empire and Alexander the Great to Napoleon, Russia, and ending with Nazi Germany. America was wise beyond its years, being populated by political refugees, freedom seekers and persecuted religious citizen. These groups saw the never ending campaigns perpetuated by governments in Europe to rule the continent. America created its own hemisphere of influence the Monroe doctrine and stayed out of Europe. WW1 Europe bit off more carnage then they could handle and America broke its neutrality to help win the day. Germany started a war knowing other European powers would be forced to defend countries they had treaties with. This was the War to end all wars. American shed their blood and capital to save Europe. After the war only two countries Finland and Canada paid back America for debt borrowed during the war. One generation later the war to end all wars created another war. America was determined to stay neutral. Leaders understood that America couldn't stay neutral forever but the people of America were tried of Europe's never ending issues. Britain started its usual game of demanding things from America. America was in bad position the people didn't want to be pulled into another war and Britain still owed money from the last war. Britain had money but wanted goods on credit. By not paying and using credit Britain hoped to tangle America into another war. America was done with this game and demanded Britain pay for its supplies with money and then later gold. Eventually America was pulled into WW2. Again America shed blood and capital to stop another European issue. After the war America did benefit from the conflict. We just happened to be the only intact country left. I don't know if it was by design or just the way things worked out but America built up its military and started protecting Europe from Communism. Every story needs a villain. Was Communism the real evil or was that the scape goat that allowed America to control Europe and disarm them. Europe has not had another conflict since the 1940's that is not because they have matured it’s because they no longer have a military thanks to America. We police the world because if we didn't Europe would and they have proved that they can’t. The world is safe today not because of America but because Europe is no longer dictating their policies to the world. Every issue in world past or present originates with policies from Spain, Britain, and France. Every issue or conflict around the world originates from policies started by these countries. From slavery to boarders can all be traced back to Europe. Yes America has its issues but no one has kept the world safer than America.