Foreign policy is a delicate manner, indeed. Our forefathers warned about entangling relationships. Regardless, as America grew, so did our interests, and as they grew, they grew outward, outward across the world. Over time, our interests eventually enveloped the span of the globe. Then, we turned to space. So as it stands in the present day, we have assets and infrastructure all-around the world. Naturally so, this is unsettling to some. If you recall in his fatwa, Osama bin Laden asserted that American presence in the most holiest sites for Arabs was a grave offense, one naturally worthy enough to him for him to attack our interests, infrastructure, and people several times, most notably, 9/11. So when you say, "Who cares," I think just about every American does.