No Americans were subject to that court so it didn't violate the constitution. Any agreement which set a foreign court above the U.S. Supreme Court wrt to I.S. citizens in the I.S. would absolutely violated the constitution. Period.
The constitution clearly lays out which court is Supreme in this country and no other court can be put above it.
The constitution clearly lays out which court is Supreme in this country and no other court can be put above it.
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