WARSAW, Poland—The German and French foreign ministers have issued a joint statement saying that Poland has both a moral and legal obligation to respect the common rules of the European Union, which it joined in 2004. Heiko Maas of Germany and Jean-Yves Le Drian of France published their statement late Friday in reaction to a Polish constitutional court ruling this week that challenged the supremacy of EU laws. The court held Thursday that the Polish Constitution has primacy over EU laws in some cases. “Membership of the EU goes with full and unrestricted allegiance to common values and rules,” Le Drian and Mass said. “Respect for and compliance with these must be fulfilled by every member state,” they added. “Of course, that also goes for Poland, which has a very central place within the EU.” “This does not just mean a moral obligation. It also means a legal obligation,” the …