I feel like I have a very average IQ but did serve in the military for a short while in the 80s and 90s. Defending ourselves takes effort and good leadership. A technological edge only lasts as long as you continue to innovate. Since we are blessed with having 2 vast oceans protecting many of our borders, the threat of being invaded by a conventional army is relatively small. So the biggest threats are civil war, nuclear, chemical/biological.
Nuclear weapons are scary for me. We keep ourselves safe by designing our systems so that even if we are attacked first, we will be able to retaliate in kind. It seems to work well enough so long as world leaders are rational. However, if a suicidal terrorist gets ahold of one, they are not rational people.
I think the best way to prevent civil war and defend our safety is through economic growth. Currently, there is to much "red tape" (if you are in business, filing tax returns is way to complicated) corruption (corporations who lobby to obtain tax loopholes or regulations that squash competition). I was willing to give someone else a try. Because a smaller number of powerful people donated to Trump's campaign, he has a smaller number of lobbiests, corporations, and special interests that he is indebted to. Trump says America has potential and promises 3-4 percent growth. Our safety nets are also not sustainable without growth. I realize he may not succeed but if he does not, there will be another election in 2-4 years. I am happy to give someone else a try but will be watching what he does.