Eye for an eye and corporal punishment are the best methods of deterrence.

If you were planning to rob a store and, if caught, faced either several years of prison or death...which one would would you be willing to take the risk with?

Thinking of shoplifting? Would spending a few days in jail or getting your hand cut off make you think twice?

Look how many career criminals and prison inmates there are in the USA and how many there are in Iran. Barbaric, yes. Does it get results, very much yes.

Remember elementary school? All the teacher had to do was brandish that paddle and the troublemakers usually shut up pretty quick! (Yes, even I'm old enough to remember The Paddle.)