Whittaker Chambers, of course, was an American version of Arthur Koestler -- the Continental/British intellectual who had really realized how he'd been snookered by the Marxists and so became more anti-communist than McCarthy, if you will.
Conservatism in the US has always meant something very different (at least since our Revolution) than in Europe, as we haven't had any monarchists since the highest of high Federalists who wanted Washington as king, and the fundamental notions of liberty and individual responsibilty are the fabric of our political philosophy. Traditionally, there was never much of a place here for the European ultramontagne Caltholic right, the unreconstructed English Tory supporter of the Stuarts or even the enlightened despotism that characterized the German and Austrian monarchies, let alone the truly reactionary views of the Russian monarchy. [Witness Bismarck's rows with the Catholic Church and the top down socialism as an instrument of control in the Prussian state and the various reforms and evolution in the dual monarchy] Those views came here mostly through intellectuals writing in Europe and through the Roman Catholic Church, especially in the late 19th and early 20th centuries as the Church fought valiantly against modernity. One needs to understand that this is the worldview in which many such as Pat Buchanan grew up.