> How would you define the difference between the action of not acting and the action of not acting, because of not making a choice to act?

I wouldn't, because not making a choice to act in a particular way is very different from making a choice to avoid as policy acting in that way, or, as was at issue upthread, “Taking a stance to not” act in a particular way. Taking a stance is (for this subject matter, at least) political. Inaction on its own is not.