I think that options are the key. The US has options. They have nukes, snipers, door kickers, booms, negotiations, and a number of other options. The more options that the US has, the more it can make a difference. For instance just because you have a nuke doesn't mean that you can use it to solve all of the problems. I nuke doesn't get used most of the time. But it gives us a lot of clout when we want to negotiate with Russia. It dose us no good when we want to stop terrorists though. We have door kickers and snipers to deal with those guys.
My point is, I think of my handgun as my Nuke. It will not get used very much, but the fact that I have it gives me a lot of control over what happens. However, the handgun doesn't solve many problems that I might face, such as my drunk neighbor shoving me on my porch, because I mowed over his flowers. Here is where my wit, knowledge of the law, and/or martial arts abilities kick in. The gun is still their, in case things get more serious, but I wouldn't use it at that time. Only having one option such as carrying a gun, only allows you to solve a limited number of problems.