It started with the Mexican-American war of 1846, so that is a viable theory (though the CIA was not yet involved). That's the war Mexicans still teach in every

It started with the Mexican-American war of 1846, so that is a viable theory (though the CIA was not yet involved). That's the war Mexicans still teach in every Mexican school with a big famous map showing that California and Texas are Mexican territory unjustly stolen by the USA.