While I agree that we shouldn't police the world, when you let small conflicts drag on they tend to escalate and drag in other countries in the region. How long do you think it would take before North Korea attacked Japan if it managed to take over South Korea? The answer is not long. Before you know it, you got a nice sized war on your hands involving half the world.
What's easier, fighting that war when we HAVE to, with millions of men or policing the world when we don't have to?
And our military isn't "spread thin". That's a load of bullshit.
"I find that the harder I work, the more luck I seem to have." - Thomas Jefferson (1743-1826)
"There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." - Ed Howdershelt