I really like your response and cant really argue with your points. I just want to add another aspect that I think you missed, the cultural mindset of the US.
Pre ww2 the US was pretty isolationist. A very, "Sounds like a whole lot of your problem and not mine" kind of country. The foot dragging for both world wars is pretty evident. I've read and personally do believe it's attributed by the fact we are a melting pot of people. That's important for the distinction of, "I left xyz country for a reason and came to this country to get away from their bullshit." That's a very toned down version of what my own dad told me on my 18th birthday when he gave me the full story of leaving soviet occupied Poland. I'm pretty sure theres a lot of grand amd great grand folks with similar sentiments when they left the old country in the late 1800s and early 1900s. People didnt uproot and enter a foreign land with no support just because they bored and doing well in their home country. This, I believe, leads to a self reliance mindset since there's a... disdain... for the rest of the world.
So the security aspect, absolutely. I think the want for all manufacturing in general stems from the self reliance, isolationist desire with security as a very good, logical excuse. However, even in bizarro world if a security argument wasn't good enough alone, this anti-global-reliance wouldn't go away.