Yemen’s Houthi militias have no ability to confront the Saudi jets that pound them with deadly airstrikes. But on the ground, they are a much more formidable foe, exacting revenge in Saudi casualties with a string of border attacks. The 870-mile-long frontier stretches from the craggy mountains in Saudi Arabia’s Red Sea province of Jizan, where deadly fighting with the Houthis tested the mettle of Saudi troops in 2009, and through the sandy deserts and basalt hills in the province of Najran, farther inland, where most of the recent Houthi attacks concentrate. These parts of Saudi Arabia were incorporated into the kingdom only after a war with Yemen in 1934, and, like many Yemenis, the Houthis—whose stronghold of Saada lies just an […]