I'm pretty sure much of history - as well as how it tends to be taught - can only be easily explained if there are a bunch of people who just love the idea of sending other people out to conquer stuff, and feeling some momentary thrill as the lines on the map move.
Sure others have some simpler to understand if no less gross motivations - "everybody" gets rich! - but history's "Fox news hosts" who weren't necessarily profiting directly still love this shit.
Adding together the serial killers, the profiteers, the Quiet Americans, and the people who see it all as an exciting game of risk, and you have a lot of support for murdering people across the globe!
Sorry it's rude to point out that people who support murderous policies are pro-murder.