helping people get rid of those cartels is something I would appreciate a lot

You’d have to be very gullible to believe they’re going to do that. EXTREMELY so to believe That it’s ALL they’re going to do.

And I highly doubt their government is able to deal with that problem on their own

Probably much better at it than US soldiers with no background in law and little to no local connections.

they are too powerful and murder any opposition

The time when fighting organized violence with more organized violence was an effective strategy ended DECADES ago. If it ever started.

The same way North Korea is stuck in the middle of the 20th century

Ethics comparisons aside, saying that the cartels (whose leaders tend to be scrupulously anonymous or known chiefly by an alias/nickname) act in the same way as the hereditary cult of personality monarchy of North Korea is so untethered from the situation on the ground that it’s currently orbiting one of the moons of Saturn.