The main reason why neither the US nor Japan tried to intercept a North Korean missile fired over Hokkaido on September 15 is that they couldn’t.
Missile expert Joe Cirincione says in an analysis on Defense One that any attempt to hit the intermediate-range ballistic missile was problematic since it was already too high for US-made Aegis or Terminal High Altitude Area Defense (THAAD) anti-missile systems to destroy.
“Neither Japan nor the United States could have intercepted the missile. None of the theater ballistic missile defense weapons in existence can reach that high. It is hundreds of kilometers too high for the Aegis interceptors deployed on Navy ships off Japan. Even higher for the THAAD systems in South Korea and Guam. Way too high for the Patriot systems in Japan, which engage largely within the atmosphere,” Cirincione wrote.
His analysis was echoed over the weekend on Japanese-language news websites and in the US press.
Cirincione notes that existing US anti-missile systems are basically designed to hit a missile in the post-mid-course or terminal phase. This is when the projectiles are on their way down and more or less headed straight at the interceptor system.
“Patriot is meant to protect relatively small areas such as ports or air bases; THAAD defends a larger area; the advanced Aegis system theoretically could defend thousands of square kilometers,” he said.
Cirincione says the only window for hitting such missiles is during the initial launch phase. But even here, the odds of hitting the target aren’t good. “There is almost no chance of hitting a North Korean missile on its way up unless an Aegis ship was deployed very close to the launch point, perhaps in North Korean waters,” Cirincione said.