Citation? It seems pretty unbelievable that a US court can order someone to do something that violates US law.
What is it you are seeking a 'citation' for? This is so obvious nobody with a legal background would question it, let alone write about it. The gp is so silly it doesn't warrant discussion. Law is not a logic game with a closed rule set, it's nonsensical to reason based on that assumption.
Just asking for an example. I don't have a legal background. No need to get defensive about it.
The government can overrule private contracts, and does so on the daily.