One ideology is premised on faith in Allah, and the other on faith in government, but what they share is that once you check in, only death gets you out. Classical Islamic law treats leaving the faith as a capital offense with no statute of limitations. The doctrine rests on a hadith in Sahih al-Bukhari, “whoever changes his religion, kill him,” and legal manuals such as Reliance of the Traveller, codify apostasy as a capital crime. Abdul Rahman discovered the doctrine still had force in 2006. He was arrested in Kabul that February for converting from Islam to Christianity sixteen...