

You got it the wrong way round. The Mexican military and navy absolutely has the means to resist in a protracted conflict and even strike back. The reason it doesn’t engage in out and out warfare with cartels is that these are integrated into rural and urban communities, are very decentralized and have no qualms about engaging in acts of terrorism to avoid capture.
Do not fall for the narrative that the cartels are in total control of Mexico, the firepower and manpower available to the state is overwhelmingly superior, but that matters very little when it comes to asymmetrical warfare. The juice ain’t worth the squeeze.
Even if that weren’t the case, narcos would be the first line of offense and sabotage for the US, they’re already terrorizing the Mexican people on a schedule that is eerily convenient to the US and have longstanding close links.

They’d also cost four million and require 500k maintenance per quarter from a company which will jack up the price every other year