I hesitate to say its unfair because I don't know how to even begin to define what fair would look like.

Look at the situation in Syria. When Obama refused significant interventions (despite his famous "red line"), Europe sharply criticized the U.S. notwithstanding the fact that Europe refused to intervene itself. This example shows how much of the world accepts and affirms the U.S. role as a so-called global policeman, at least when it suits them.

Now imagine a situation where the U.S. bowed to pressure and intervened at Europe's behest, but subsequently was drawn into an ICC prosecution for some action in that country. That hardly seems fair, to assume both the direct cost of the conflict plus the cost of ex post criticisms by parties unwilling to participate themselves. Especially in light of the fact that, relatively speaking, the U.S. has well functioning military courts willing and capable of punishing crimes, particularly the types of serious crimes the ICC was established to handle.

The existing situation is unfair in the sense that the U.S. is a wealthy hegemon, while most countries are poor and vulnerable. But the U.S. putting itself under ICC jurisdiction wouldn't substantially change that. It's such a complex situation I find it hard to criticize the U.S. here. I sort of like Clinton's approach of "plausible ratification", which appreciated both the real politick and idealist aspects. It lent the court legitimacy without risking a crisis where the U.S. repudiated jurisdiction or where the threat of repudiation caused ICC prosecutors or judges to pull their punches. Situations of the latter type would slowly erode the ICC's legitimacy.