Friedrich Merz, a man who has never held a government role, is preparing to take the reins in Germany just as the country faces its biggest economic and diplomatic crises in decades and Europe looks urgently for a new generation of leaders for an era of transatlantic tension.

Germany's conservative leader Friedrich Merz said on Thursday the U.S. was at risk of sliding into longer-term authoritarian instability, casting doubt on Washington's presence for Germany’s 70th NATO membership anniversary in May.