Earlier quoted context omitted.
And a lot of that violence spills over the border into the US. Bloody cartel murders, extortion, and such are common in the southwest US and beyond. The Mexican government and politicians are all somewhere in between being controlled by the cartels and too scared to do anything about them. That is casus belli , legal grounds for war, by any reasonable understanding of international law.
If the US actually started using its military to hit these guys, what would stop them from sending a thousand guys into a large chemical or nuclear plant and creating a disaster that wiped out a city, or more? I find this sort of jingo rhetoric disturbing because the US has never faced an enemy with thousands of troops inside the US and the funding of a nation state. I can imagine an idiot like Trump actually startin…
I mean, yes, they could, but would they? What would be the realistic result of such an action? Would the US then stop and go “Well, I guess we’ll have to stop antagonizing the cartels.”. I would guess that such a thing would instead be a Pearl Harbor moment, and I think the cartels know this, too. The cartels don’t want to act out your personal nightmare scenario; they want to do things to make the US stop bothering the cartels. Instead of mindlessly scare-mongering, figure out what that action would be, and ask yourself if a war with the cartels is worth it. It might or might not be, but be realistic about it.