Yup, in times past this would be considered an act of war. I hope in my lifetime we invade that 3rd world ceasepool and civilize it. What an absolutely useless country.
We had our chance in 1848 and blew it (because we couldn't see the future :-) )
IMO, if we had stayed there, Mexico would be as prosperous as Texas clear down to the Guatamalan border.