Permanent armed neutrality for the US?
From a (hopefully informed) Swiss point of view, this position is quite untenable. Firstly it displays a lack of understanding of the very different relative weights and statures of the two states in the world. The Swiss David has come to accept neutrality as his preferred mode of operation in the highly pugnacious European environment after 1600 because he lacked power and direction to behave otherwise. Proof of that hypothesis is that before the period of the growth of strong nation states, the ancient Swiss were a highly respected military great power with a fairly expansive streak. But after some strategic defeats, the virtue of neutrality in my view is a lack of opportunity rather than a deliberate policy decision. For a small state like Switzerland, neutrality and the pursuit of law & order in international relations makes sense.
Secondly, for the US Goliath with its unsurpassed economic & military resources, the world looks quite different. Any administration that would deliberately dispense with the creative options it has at its disposition in persuing its own interests would give way to either less reluctant foreign powers or a more "activist" administration. Here, the temptation to resist is power-driven unilateralism - a temptation to which the current administration obviously has trouble resisting.
In international relations, thirdly, power and the horror vacui relative to power is just a reality, to be moderated by international law. Having the most powerful state on the globe withdraw into its own shell will not help anyone, as we we were forced to observe when the US was going through one of its isolationist phases.
Being liberal in the classical European sense, I very much believe in the non-coercion principle promoted by Perry, but this principle unfortunately has a very weak standing in the world of international politics, which ultimately is about power, i.e. force & coercion.
P.S. With the evolution of a more cooperative environment in Switzerland's immediate neighbourhood, traditional neutrality and aloofness is coming under increased pressure lately. For example , the Secretary of Defense has recently called for a debate about universal conscription upon which the Swiss militia is obviously based. Consequently, many of those sham Chalets are up for sale or demolition now.