I think it's complicated. What is an act of war, and what is a crime? Should the losing side of wars be jailed? Is death from warfare really that unfair, for a person committing acts of war, just without permission from a government? Is it fair to jail a person you were at war with, who isn't even a citizen of your country? Do you really have police powers over people you are fighting, who might not even be in your own country, when captured? Also, is holding them in detainment, the same as putting them on trial, like a criminal? Can you gather evidence for a fair prosecution, in the middle of a battle? So many questions about this topic. It's a tricky one.
Taking the life of a terrorist is not murder..... but being a terrorist and taking the life of an innocent bystander is murder. The correct translation of the commandment should be.... "Thou shalt do no murder. " "Thou shalt not kill" is actually a mistranslation. Is it lawful on the Sabbath to do good or to do evil, to save life or to kill?