Dan, I think the fact that about 40 of those 50 years were spent seeking an end to a particular totalitarian regime skews the figures on Kevin Smart’s claim (and I’d note that he wrote it in mid-2002, before the invasion of Iraq and while the Afghan mission was still principally about hunting down al-Qaeda and its Taliban enablers). Given the Cold War, and the fact that the totalitarian Soviet regime spawned various Soviet totalitarian satellites that we were also trying to defeat, how could anyone deny that during the half-century prior to mid-2002, conservatives had generally favored a foreign policy of seeking to end totalitarian regimes?
Still, acknowledging this to be true, and agreeing that we should both oppose totalitarianism and promote real Western liberalism, are a good distance from saying we should seek to end totalitarian regimes by militarily invading and occupying countries until they form something we think (or at least some think) approximates democracy. Supporting those countries in establishing constitutions that establish Islam as the state religion and install sharia as a principal source of law is not a prescription for ending totalitarianism; it is instead the substitution of one form of totalitarianism with another that we hope will be less draconian.
Moreover, the prohibitive cost in blood and treasure of these exercises, coupled with the small (or non-existent) return in increased U.S. security, makes it less likely that we will deploy our military when we really should. That is, if nation-building is now to be understood as part of the price-tag for military interventions, the inevitable result will be that we refrain from intervening in some instances when we should intervene. That is a boon for totalitarianism, not a way of ending totalitarianism.