I still stand by my opinion. You kill the enemy wherever you find them, in whatever form you find them; you hammer on them, their families, their society, and their culture until they collapse under the weight of the attacks.
Fight to the finish or don't fight at all ... just roll on your backs and surrender, if that's the attitude that you want to take.
Absolutely, especially when YOUR side is the one attacked first.
Sand Creek is just a bad analogy. Hiroshima, the ultimate endgame of the attack on Pearl Harbor, might be a better one.