It's interesting how Kirk was attempting to get primitive people to rise up against the technologically advanced Klingons. No advanced weapons. A willingness to follow the dictates of the occupying force. Kor didn't start killing the Organians until Kirk started blowing stuff up. Is this standard Federation policy? Should he be sacrificing a primitive people in order to protect the Federation? Does the Prime Directive allow you to use primitive people as cannon fodder?
"You see, Killbots have a preset kill limit. Knowing their weakness, I sent wave after wave of my own men at them, until they reached their limit and shut down."
- Zapp Brannigan - Love's Labours Lost in Space
If I recall, once the Klingons started killing hostages, Kirk and Spock gave themselves two hours to go on a 'suicide mission'.