Why has Obama bound us to a war in Libya? Humanitarian reasons?

If that is true, then why are we not fighting in Sudan, Iran, Bahrain, Saudi Arabia, China, Syria, Yemen and the Ivory Coast? Don't get me wrong, I don't care at all about Libyans or any of these other backward, idiotic countries. I just want to know why helping Libya is worth the deaths of our fellow soldiers/countrymen, yet these other countries are not.