Te Anau, that was an interesting paper, thanks for the link. Out of curiousity, did you actually read the entire paper?
What the paper demonstrates is not so much a consistent pattern of enmity maintained by Mexico against the United States, but rather a calculating promotion of self-interest by an independent nation (otherwise known as Realpolitik or "looking out for Numero Uno"), which pretty much charactized all of the parties involved and frankly is what countries do. How exactly are you going to fault the government of Mexico for looking out for itself and its economic interests, especially when (as the paper documents) their rival to the north had taken to punishing it for its economic policies?
Furthermore, what the paper does not demonstrate is that Mexico posed any serious military risk to the United States at the time. I found the discussion of Hoover's exaggerated reports concerning possible Axis activities and threats originating in Mexico quite telling and not all that dissimilar from some of the more histrionic perspectives that inform debate about this issue today. That FDR used this to his advantage is, again, not entirely unexpected; how many times have we heard the 'War on Terror' used to excuse all sorts of government programs of dubious wisdom or legality?
And, again, what does this have to do with the issue at hand or the points that you have made within this thread? To say that the governments of the US and Mexico haven't always been on the best of terms, or haven't always trusted each other, or haven't played diplomatic and economic games with each other isn't particularly enlightening. However, if that is the measure of an enemy, then pretty much every government in the entire world should be perceived as our enemies. This is why precision in language is important, and the application of labels like 'enemy' with too great haste and emotion are unhelpful at the very least.
For example, I quote Pointer's post above:
Perhaps our "government is the enemy?
In what way is that even a remotely helpful statement?
You still haven't answered my question as to what possible benefit you feel would be derived from another civil war within this country, but I suppose that should be a different thread.