I think I'm beginning to understand now.
(For a number of reasons) The US does not recognize the jurisdiction of the International court of Justice in the Hauge. That means that any findings of that court will be regarded as non-existant by the US. It has happened before (for example, when Nicaragua took the US to court in 1980-something, Nicaragua won (apparently it is illegal to mine harbours in other nations, and train insurgents to overthrow the government) but so what? Since the US has not recognized the court, they are not bound by its rulings).
Now, the ICJ in the Hauge is the court that handles all war crimes trials (like modern Nuremberg) and there are some US servicemen that might be interesting for that court (for example, the US attacks against Serbia and Kosovo was completely against international law) so in theory the court could issue a warrant on some US military personell.
But since the US does not recognice the ICJ, this might lead to a problem.
But I seriously doubt we will see the USMC storm ashore on the beaches of Holland anytime soon.