The Cost of Freedom

Why is it that the United States can't let some other countries deal with a problem for once? I mean were in the middle of a war in Afghanistan and we came pretty close to adding another war to the list of wars were currently in. I know that America is one of the worlds remaining super powers and that many of our decisions effect the world but come on can't we just let the British or French handle the Libyan conflict so we can focus on ending the war in Afghanistan. The British have less than 10,000 troops in Afghanistan while the United States has well over 50,000 troops. So I'm sure they could spare to send some troops over to Libya but, no the United States once again has to be the one in charge that uses way more of its resources in a conflict then any other country. This isn't to say that I am against freeing countries from dictators but we really need to let somebody else handle something every once in a while.