If you were going to complain about wasteful spending and failing projects in the DoD, I would respect your reasoning more. Instead, when it got to "humanitarian this, environmental that" you turned into Charlie Brown's teacher.
I don't know why anything "humanitarian" should be taken with a grain of salt. You surely are not going to argue that something like the Syrian humanitarian crisis is comparable with a cartoon character?
On the environmental side, I am not surprised to see people raising eyebrows, because the US military's impact there is vastly underreported. A lot of effort went into exempting the US military from the Kyoto Protocol - and that's for a good reason, since the US military alone emits more CO2 than many industrialized nations. So if you don't believe in global warming, there's nothing I can do to reason with you. But if you do, you might realize that the environmental impact alone might be more damaging than some of the other items I mentioned.
Think of it this way - if the US military cleaned up its act, we could remove the emission control devices from all US cars and still come out on top.
