Donald Trump has disrupted the global economy with his disastrous tariff wars and appears hell-bent on gutting transatlantic relations. I am hoping he has also unwittingly injected new life into the EU’s struggle to wean itself off overreliance on Washington. A vast network of trade and aid agreements connects the EU with more than 70 countries. The union could become an important standalone global actor and even thrive in a multipolar world. But it must first shed its Eurocentric worldviews, complacent policymaking and double standards. The omens are mixed. Ursula von der Leyen, the president of the European Commission, has...