I am sorry I am not sure what you are talking about there. The morality of promoting patriotism? I didn't think I was engaged in a defense of the practice of the military promoting patriotism.
And yes, I most certainly believe that there are some humans that need to be killed. And, I am glad you live a life where that harsh reality can seem absurd to you, but please recognize people have fought hard, died, and yes killed so you can enjoy that.