There's no overarching EU law. There are EU regulations and directives, and the member states (who each have their own state laws) must fold those directives into their own state laws in a way that fits. The regulations tend to be very targeted.
So in a manner of speaking, it's all state laws, no "federal" law, just local interpretations of "federal" directives and some common standards. And contracts in each state have to follow state law. If someone objects that a "federal" directive is broken, then they can sue the state in an EU court, etc.
A big difference with America is that a legal precedent in one state doesn't mean anything in another state. It often doesn't mean anything in the same state either. The judges interpret the legal texts, but do not create new case law. You can't refer back to some judge such-and-such who said something was ok in a similar lawsuit, so therefore it must be ok going forward in all future lawsuits.
That's a meaningless statement. The politicians frame the engagement, but that has always been the case in all wars everywhere. Read Clausewitz. There are parameters and objectives. If a general can't deliver within these parameters, it means he's not good enough.
Same if your boss is telling you to build some accounting software, and you complain that it's impossible and he should let you build a flight simulator instead.
My idea of roughing it turning the air conditioner too low.