MUNICH, Germany — European Commission President Ursula von der Leyen on Saturday told the Munich Security Conference that the EU should get serious about its own mutual defense clause.

Article 42.7 of the EU treaty has been floated as a Plan B for Europe’s security, in a world where the U.S. decreases support for NATO.

Like NATO’s once-ironclad Article 5, which U.S. President Donald Trump has repeatedly cast doubt on, the EU clause obliges countries to provide “aid and assistance by all the means in their power” if another nation in the bloc is attacked.

“I believe the time has come to bring Europe’s mutual defense clause to life,” von der Leyen said, without providing specifics. “Mutual defense is not optional for the EU. It is an obligation within our own Treaty — Article 42(7) … It is our collective commitment to stand by each other in case of aggression.”

While Munich discussions on Friday largely centered around the need for a strong European role in the NATO military alliance, von der Leyen’s remarks underscore that Europe may need to hedge its security bets given Trump’s unpredictable attitude toward historical allies.

The push to use the EU’s mutual defense clause comes amid the worst transatlantic crisis in decades, with Trump’s claim to Greenland shaking belief in the U.S. commitment to NATO.