Maybe it isn't isolationism, but it isn't a trickery to call it such. If you offered the text of the Libertarian platform on international affairs, many was say it describes an isolationist policy, without intending trickery.

Also, whatever the position libertarian take today, there have been strong isolationists who have been key members of the movement, like Murray Rothbard who said, "The libertarian position, generally, is minimize State power as much as possible, down to zero, and isolationism is the full expression in foreign affairs of the domestic objective of whittling down State power."

http://www.lp.org/platform -- American foreign policy should seek an America at peace with the world. Our foreign policy should emphasize defense against attack from abroad and enhance the likelihood of peace by avoiding foreign entanglements. We would end the current U.S. government policy of foreign intervention, including military and economic aid.