Out in the field, they're called the blue helmets: the peacekeepers. They keep simmering conflicts from bursting back into flame. The international assignment of such UN missions is laced with controversy (and fair enough). It's usually a scorched war zone where soldiers are being sent.
Now, a new diplomatic battle is underway. American officials say their soldiers won't don blue helmets unless they're granted immunity from the International Criminal Court. Allies are crying "Horse-feathers!", accusing the U.S. of playing politics with peacekeeping.
At the pointy end of this controversy: an American discomfort with putting GI's under other nation's generals, other nation's justices, and other nation's scrutiny.