Why did Theodore Roosevelt receive the Nobel Peace Prize? Explain.

Theodore Roosevelt won the Nobel Peace Prize in 1906,
while he was President of the United States.  He won it mainly for his efforts to end
the war between Russia and Japan that is known as the Russo-Japanese War.  This is
somewhat ironic because he is known as an aggressive president who was willing to use
America's military might to get its way.

In 1905, Roosevelt
invited both Japan and Russia to send delegates to the United States where he would
mediate between the to try to find a way to end the war.  Roosevelt wanted to do this
largely because he believed that great powers like Russia and Japan should each have
their own "spheres of influence" and that they should not try to take pieces of those
spheres from others.

Because he successfully helped the
Japanese and Russians to negotiate the end to their war, he won the Nobel Peace
Prize.