True, but we should point out to these folks that we are the ones defending their nation, and we could start getting tired of it if they don't start helping us.
Defending them from whom exactly? If we leave, will the North Koreans pile into a none existent amphib. fleet and invade? The Chinese? Bin Laden and company are warring against the U.S. because we have troops in their home countries and we have a history of propping up their repressive governments (not that OBL has a less oppressive government model in mind, but his appeal to history and current events touches a nerve - no doubt).
If I'd told you in 1990 that sending hundreds of thousands of U.S. soldiers to the Middle East to put an arab king back on his throne would result in the twin towers falling and 3,000 U.S. dead (nevermind the billions of tax dollars wasted), would you want to do it? Is that what America is about? Going around the world restoring monarchs that former European colonial powers put in place? My own reading the Declaration of Independence leads me to hold otherwise.