Pakistan, Oct. 3 -- Some threats start out local and end up belonging to everyone. When a militia with no state behind it can strike far past its own borders, the problem stops being regional and becomes a worry for every capital that depends on stable energy and trade. The Houthis fit that description. A fight over Yemen's future has grown into a challenge to state sovereignty, regional security and freedom of navigation, and into a test of how much the world will tolerate from armed groups. The Middle East is facing a more dangerous reality, and Pakistan cannot treat it as somebody else's problem. It has made a point of spelling out its position plainly rather than leaving it to guesswork.

The Houthis have worked out that location is p...