Also, our factories were in full-out build mode. We could have built as many nukes as we needed as soon as we needed them; along with the bombers to deliver them.
As far as insurgencies go... that's kind of my point. If your civilians are armed, then you can never truly (at least not for a long, long time) conquer the nation. You can uproot its government, but unless you show some strength and discourage insurgency (an area in which we have admittedly failed in Iraq), you will have troubles for quite a while.
So if you take away civilians' guns, any insurgency will pretty much be "I don't like you being here! Go away or I'll hit you with a hoe!"
And that's not what we want in the US if someone (somehow) takes over.
As for MiG-25s, their engines burn out if they reach maximum speed... And it was only prototyped in '64; it entered service in '70, just 2 years before the F-15, which whips its A**.
And the MiG-31 sucks almost as badly; especially compared to the F-22 and F-35.

Even the Su-37 is nothing compared to the US's new aircraft.
And if Canada and Mexico attacked the US... here are the figures:
Canada: about 110,000 Military Personnel
Mexico: about 620,400 Military Personnel
USA: about 2.3 million Military Personnel
Figure it out.
-
m