If invading another country can be reduced, in its essence, to “we are good, they are bad” then this effectively gives carte blanche to those in power with bad intent. They just need to easily manipulate the masses into thinking that Country A is bad.
The U.S. has been fantastically inconsistent when it comes to intervening for humanitarian reasons. It has effectively become the case that if those in power don’t like the leadership in a given country they just need to drum up moral outrage in order to unleash our military forces. This is a bad state of affairs because it is so easy to paint a given country in a bad light. Since thoughtful consideration is not a requisite for military action we tend to engage in military conflicts for dubious reasons and for short terms goals without considering long term implications. This is bad as I see things.