How do modern American missile defense systems demonstrate advanced capabilities in protecting allies and what makes exo-atmospheric interception so significant?

Recent military operations showcased America's advanced missile defense capabilities when Iran launched approximately 400 drones and missiles at Israel. The U.S. military effectively intercepted these threats, treating the scenario as both a defensive operation and a training exercise for pilots to gain real-world experience. The most significant advancement demonstrated was the SM3 missile system's ability to intercept targets outside Earth's atmosphere - a feat accomplished from sea level. This exo-atmospheric capability represents a revolutionary leap in defense technology, as traditional air defense systems typically operate within the atmosphere and work best when protecting their immediate vicinity. This technological superiority not only provides unprecedented defensive coverage but also serves as a psychological deterrent to adversaries, demonstrating America's ability to neutralize threats at extraordinary ranges and altitudes that were previously thought unreachable.