Pirates.

While it may surprise many people, pirates not only exist, but in places like the coasts of Malaysia and Somolia, are actually common. Real pirates are low on charm and high on brutality. Like genocides in Sudan, piracy is another reason why I am not a pacifist. There are times when naval military force is called for, and defeating pirates is an easy example of such a time.

Now, in truth, the United States has a navy very ill suited for this kind of mission, it is primarily a "blue water navy" designed to fight the Soviets in the Atlantic, the Pacific and the Arctic. But, the proposed littoral combat ship, the first of which are under contruction now, would be perfect for this kind of mission.