Back in October - Mexican official confirms cartel gunmen forced a dozen tanker trucks to dump gasoline at gunpoint
U.S. Reps. Henry Cuellar, D-Texas, and Dan Crenshaw, R-Texas, also signed the letter, which accuses Mexico of trying to “nationalize its economy and renege on its commitments in the USMCA as a means of empowering its failing state-owned petroleum company.”
Nationalizing it's economy and thwarting our not so covert attempts at undermining it! The horrors!
What about the spirit of the US Mexico Canada Agreement ?!
USMCA more like US Marine Corp Agreement 
Plus, gasoline is far more expensive in Mexico, by about 125% in some instances.
Also Californians Flock to Mexico for Cheap Gas as Prices Rise to $6 in State
Californians are traveling to Mexico for cheaper gas, as fuel prices surge following the Russian invasion of Ukraine, according to The San Diego Union-Tribune and the Los Angeles Times.
Awwwww is Mexico kind of immune to your sanctions shitfuckery becauss it nationalized it's oil and gas? 
Nah, it's just so it wouldn't be called Canada US and Mexico deal, which it was rumored Trump wanted it called. But unfortunately we were not allowed to live in the world where "Trump signs CUM Act" becomes a legitimate headline.
Not sure why they didn't call it USMECA. Mexico's the only one getting one letter, and I don't see why that would be except for making sure Mexico knows its place or something like that. It's more pronounceable as well.