Actually, PDiddie, with the caveat that i am as opposed to the militaristic posturing of the administration as are you, you are incorrect to assert that this is:
Quote:History's first instance of America choosing to invade and occupy a sovereign nation that poses little discernible threat to this country or our allies.
After Tejas had "achieved it's independence," Mexico basically took the position that the Republic of Texas did not in fact exist, that it was a rebellious portion of one of los Estados Unidos de Mexico, and that any attempt at annexation by the United States would be a war of aggression. To the extent that the capture of Santa Anna at San Jacinto, and his "ransom" by means of an agreement to acknowledge Tejano independence was repudiated by the Mexican government, their position had merit in international law. Although there was not a formal body of international jurisprudence at that time, there was a concept of the "Law of Nations," and it was recognized by the United States--the evidence is in the use of that exact phrase in one of the clauses of Article I, Section 8 of our Constitution.
When Polk encouraged the application of Texas for admission to the Union, he knew full well what he was about. Zachary Taylor was sent with a small force of professionals (a good account of this is in Grant's memoirs, he being a newly-minted infantry officer then) to the region between the Pecos and Rio Grande, which was a concious provocation. Thereafter, the predictable Mexican attack on this force was the ostensible
casus belli. In terms of dead, wounded and missing as a proportion of total forces committed, this was the bloodiest war in which we were ever involved. But hey, we got Colorado, New Mexico, Arizona, Nevada, California--hmm, wonder if it's too late to give it back.
Polk was justifiably vilified by his political opponents at the time, and his strenuous efforts to assure that Winfield Scott would not be able to capitalize on the war in a bid for the presidency actually cleared the ground for the election of Zachary Taylor. Mexico posed absolutely no threat to the United States, even after the admission of Texas. The disputed strip of land between San Antonio de Bejar and the Rio Grande could easily have been dealt with by negotiation and purchase. But then, we could not have stolen all that real estate from them.