GOOD QUESTION: What stopped Japan from intercepting North Korean missile?

The projectile was apparently tracked by the three Aegis destroyers, each equipped with Standard Missile-3 interceptor missiles that are constantly deployed in the Sea of Japan. A second layer of close-in defense is provided by the Air Self-Defense Force’s ground-based Patriot Advanced Capability-3 missiles, with the ASDF’s PAC-3 unit in Hokkaido based at Chitose Air base.

“By the time this got over Japan, this thing was very high and moving extremely fast,” Lance Gatling, a defense analyst and president of Tokyo-based Nexial Research Inc., told DW.

“It was apparently at an altitude of 550 kilometers when it passed over Hokkaido, which is at the very limit of the intercept range for the SM-3, and any Aegis destroyer would have needed to be in just the right position to intercept,” Gatling said. “All in all, it was a pretty low percentage shot if they had gone ahead and ordered it.”

Boost-phase is when an ICBM is most vulnerable, but also the most difficult time to arrange an intercept.