At the same gathering of top security officials last year, Vice President JD Vance had attacked European allies, triggering a series of confrontations. BERLIN/MUNICH, Feb 13 (Reuters) - U.S. Secretary of State Marco Rubio warned transatlantic ties faced a “defining moment” in a rapidly changing world but struck a warmer tone ahead of the Munich Security Conference on Friday after a year of unprecedented upheaval. At the same gathering of top security officials last year, Vice President JD Vance