Quote Originally Posted by Dayuhan View Post
Because at times we may see fit to assist in operations that are primarily someone else's responsibility, just as at times we seek the participation of others in missions that are primarily ours.
The canonical case is the mutual defense treaty, the principle feature of which is quid pro quo. Precisely what take do Americans expect from their partners in exchange for "participating?" Why would anyone think of the single largest contributor to the Coalition as anything other than the most interested party in the operation? More importantly, why would they consider themselves in America's debt as a result?

Doesn't have to be all or nothing, control or avoid.
We're not discussing command arrangement here; a pointless exercise given that the "coalition" members are more or less acting autonomously. But since you bring it up, the notion that the United States is "supporting" allied operations is belied by her independence of action.