Absolutely false. Both in the sense that Rothbard took "America," and in the sense that Wheeler and most other conservatives take it.
Rothbard actively inveighed against the automatic identification of a group of people with the State that rules over them. "America" in its productive, individual-created, economic, private sense was what his writings exalted constantly. Anyone who samples his four-volume (and sadly never finished) history of the Colonial and Revolutionary periods, Conceived in Liberty, or his defenses of entrepreneurs in all eras among his other books, will grasp this at once.
He, however, also constantly dissected the tyrannies -- that last word has gone out of favor on FreeRepublic recently -- of the unconstitutional and lawless State that rules over us. Even in the sense of pointing out just how the power-mad rulers the world over were essentially alike in their depredations, despite varying hallowed paper barriers of whatever vintage.
(I'm reminded of a famous cartoon showing FDR making a jocular late-'30s phone call to Stalin: "I'm glad you managed to write a constitution, Joe! I can't find ours!" It illustrates a new edition of John T. Flynn's Roosevelt Myth, from an author that Rothbard devoutly respected as part of America's anti-statist and pre-Buckley "Old Right.")
As to this particular quote Wheeler dug out of context, it was referring -- as Rothbard often did, in assessing political situations -- to how a countervailing power abroad can check the controlling ambitions of statists that are far closer to home. It wasn't that the Soviet State had any virtue -- it was that, for Rothbard, checking the Soviets' influence prevented the American State from stomping more firmly on our own virtues. Especially when free people were needed whose substance could be seized, conscripted, or directed to feed the machines of our supposed "national defense." The latter days of "our" State being a "hyperpower" have not made Americans or their enterprises any more secure among those abroad.
Rothbard despised all States and all tyrannies, foreign or domestic. He gave no particular favor to what has become a failed American experiment in constitutional and limited government. He pointed out at length -- see his Power and Market -- how it carried the seeds of its own demise. As many around here have also acknowledged ... well, until there was yet another "war on."