Ah, but it was the Manifest Destiny of the USA to conquer North America and Mexico happened to be in the way. How much more justification do you need?
(Note, I grew up in Canada, which became a single country for mutual defense in case the USA wanted to repeat the incident on its northern border. Details are a bit more complicated than that, but that is the gist of it.)
(Note, I grew up in Canada, which became a single country for mutual defense in case the USA wanted to repeat the incident on its northern border. Details are a bit more complicated than that, but that is the gist of it.)