An Eagle and a Cactus

Say, in the heat of the Cold War (hehe) Leftist elements gain control in Mexico. These partisans could either be democratic socialists or Stalinist tyrants, democratically elected leaders or violent revolutionaries.

For the US all that doesn't matter, because 'If It's Red, It Should Be Dead', and American forces soon roll in.
So, what happens to Mexico? Other than the likely US-supported Generalissimo who would take power, does the US annex some territory, such as Baja California? Does Mexico seize to exist, splitting into the likes of Yucatan and Rio Grande?

Of course, in addition to describing the aftermath, posters are also free to theorize about how such a sequence of events could happen.
 
Say, in the heat of the Cold War (hehe) Leftist elements gain control in Mexico. These partisans could either be democratic socialists or Stalinist tyrants, democratically elected leaders or violent revolutionaries.

For the US all that doesn't matter, because 'If It's Red, It Should Be Dead', and American forces soon roll in.
So, what happens to Mexico? Other than the likely US-supported Generalissimo who would take power, does the US annex some territory, such as Baja California? Does Mexico seize to exist, splitting into the likes of Yucatan and Rio Grande?

Of course, in addition to describing the aftermath, posters are also free to theorize about how such a sequence of events could happen.

I think what exactly happens is highly-dependent on which particular President is in the White House at the time. Probably worst-case scenario for Mexico would be if this happens during Reagan's presidency, in which case the United States would probably not annex territory, but would force permanent leases on military bases establishing throughout Northern and Central Mexico. The bases in Northern Mexico will likely be active participants in the "War on Drugs" (i.e. "Operation Eliminate Competition") and will contribute to instability in the country. Would likely also see a base or two in Chiapas. It's remote, the personnel there are unlikely to come into scrutiny, and it allows the US to project power against Centroamerican states and fight leftist insurgents based in the rugged south of Mexico. Mexico will still exist. Balkanising it de jure opens all sorts of cans of worms, though I guess to an extent Mexico has been de facto balkanised IOTL.
 
Was US forces even needed? Just a domestically-produced coup d'etat would do. I don't think any leftist force could out-fund the Army than the Americans.
 
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