This is not a cave in to the U.N. it's an extension to the debate while placing an umbrella over our troops from politically motivated war crimes charges. If we were to piss off every nation by pulling our troops from areas where we are needed most for peacekeeping missions, meanwhile... at the same time we are asking for their support in fighting our war on terrorism, we would be burning a lot of bridges by withdrawing our troops from around the world (which would result in caotic situations in some cases) and possibly force some of our allies to discontinue their support of our efforts.
This is politics on the world stage... That's all. No cave in just postponing a crisis