It's not the only cause (I'll save you the rant on US defense spending, you can watch Why We Fight (http://www.imdb.com/title/tt0436971/) , but it's a positive feedback loop. I don't believe I used the word "led" or suggested one caused the other. I am suggesting that once gun ownership (and concealed carry) and police militarization are established, one reinforces the other.
Ah, you said blame them. I'd assumerd that meant you felt they were the cause of both. I was pretty confused. Thanks for clearing that up.
I am a fan of responsible firearm ownership, but not the NRA - by the way. I don't know if I'd blame them, but I'd agree that they contribute to the 'gun culture' that ends up with irresponsible people wanting to own firearms.
9/11 and the two wars led to police militarization. Directly due to funding to Police departments to purchase ex-military weapons and indirectly by hyping the terrorist threat.