"Our military expenses have not been high to protect Europe, but rather to protect our interests. Sure, European countries enjoy national health car, free education, long vacations and so on, but they are paid for by much higher taxes. They have allowed their militaries to become small for two reasons - a lack of a major continental threat when the Soviet Union crashed, coupled with the US maintaining the attitude that we were more comfortable when Europe was "owing us one" and having bases throughout the continent than looking at an armed Europe from outside (as we did before the Second World War)."

The argument against Europe in the Nato debate is a total canard. Ok, on the surface they never paid their 2% but was it really that much of an issue? As you correctly point out we got to have our bases all throughout Europe and our defense contractors supplied the majority of armaments. From Europe's perspective nothing was broken with the arrangement and hence no need to heavily invest in military. It was all mutually beneficial.

Now that's not to say that the US shouldn't have gently nudged NATO counterparts to invest more. Almost all presidents did before but they were also acutely aware of the aforementioned benefits that came along with the alliance. Trump has been hostile to Europe from day one. That is not only negligent but frankly speaking downright bizarre!