Is missile defense useful?

Japan's missile defense system invariably draws much attention every time a firing of a ballistic missile by North Korea appears imminent. The news media in this country have lately carried a wide variety of reports on whether that system would be effective, as there appeared to be growing signs of Pyongyang firing the Musudan intermediate-range ballistic missile.

But the true value of the missile defense system lies not in its ability to intercept or shoot down flying weapons, but rather in its effectiveness in persuading the adversary to give up the idea of firing a missile for fear of it being shot down. And an important underlying factor in the missile defense system is the fact that the missile defense system of the Japanese Self-Defense Forces complements that of the U.S. armed forces.

In other words, the missile defense system is a weapons system that symbolizes the Japan-U.S. alliance.