Ilya Somin of The Volokh Conspiracy:
In my view, targeting terrorist leaders is not only defensible, but actually more ethical than going after rank and file terrorists or trying to combat terrorism through purely defensive security measures. The rank and file have far less culpability for terrorist attacks than do their leaders, and killing them is less likely to impair terrorist operations. Purely defensive measures, meanwhile, often impose substantial costs on innocent people and may imperil civil liberties. Despite the possibility of collateral damage inflicted on civilians whom the terrorist leaders use as human shields, targeted assassination of terrorist leaders is less likely to harm innocents than most other strategies for combatting terror and more likely to disrupt future terrorist operations.
Agree. The only better scenario would be to capture him live to be put on trial, however that would probably be too much public relation trouble for an American President to desire.