The construction of homemade bombs has long been a cottage industry for insurgents and terrorists. From Al Qaeda-linked militants in Southeast Asia, to insurgents in Iraq and Afghanistan whose roadside IED's have caused the most casualties in those two wars, cells typically rely on a small cadre of skilled people to build their bombs, and that cadre's skills invariably improve if they avoid capture or death.
That makes Asiri a crucial target for the Saudis, the Yemeni government, and the United States, which has grown increasingly alarmed at evidence that a self-contained and competent offshoot of the original Al Qaeda is now flourishing in Yemen's lawless tribal regions.
Asiri appears to be the "getting things done guy" and if so, his arrest or assassination is probably now at the top of the US's target list, above even Yemeni-American cleric Anwar al-Awlaki. While Mr. Awlaki, charged by Yemen on Tuesday with inciting violence against foreigners, is also a target, the fiery preacher is more of an ideologue than an operative.