For years, the scrappy Iran-backed Yemeni rebels known as the Houthis did such a good job of bedeviling American partners in the Middle East that Pentagon war planners started copying some of their tactics.

Noting that the Houthis had managed to weaponize commercial radar systems that are commonly available in boating stores and make them more portable, a senior U.S. commander challenged his Marines to figure out something similar. By September 2022, Marines in the Baltic Sea were adapting Houthi-inspired mobile radar systems.

So senior Pentagon officials knew as soon as the Houthis started attacking ships in the Red Sea that they would be hard to tame.

As the Biden administration approaches its third week of airstrikes against Houthi targets in Yemen, the Pentagon is trying to thread an impossibly tiny needle: making a dent in the Houthis’ ability to hit commercial and Navy vessels without dragging the United States into a prolonged war.