Why the SM-3 Can Intercept the YJ-21
The SM-3 (Standard Missile-3) is designed to intercept ballistic missiles in their midcourse flight phase, and it possesses capabilities that could theoretically allow it to engage the Chinese YJ-21 hypersonic anti-ship missile.
The key reason lies in the YJ-21's flight profile. To achieve its reported long range (around 1,500 km), the YJ-21, as an anti-ship ballistic missile (ASBM), must follow a ballistic trajectory during its midcourse. This means it is boosted out of the dense atmosphere and spends a significant portion of its flight in the vacuum of space or near-space, coasting towards its target.
The SM-3 is an exo-atmospheric interceptor, purpose-built to operate in this very environment. It launches from Aegis-equipped warships or Aegis Ashore sites, and its kinetic warhead is designed to directly collide with and destroy ballistic missile threats while they are outside the atmosphere.
While the YJ-21's extreme hypersonic maneuverability in its terminal phase (as it re-enters the atmosphere to strike a ship) makes it incredibly challenging for close-range defenses, its midcourse ballistic-like trajectory in space presents a window of opportunity for the SM-3 to engage it. Success would depend on factors like early detection, accurate tracking, the ability to discriminate against potential countermeasures, and the strategic positioning of the SM-3 launch platform.
