I think there's some throwing-of-babies-out-with-bathwater in Shadia Drury's critique and the typical linking with the moralism, dishonesty and epistemological hubris of the Neocons. Strauss' theory of the importance and role of political morality, of the need for "noble lies," of the split in leadership between philosophers and "gentlemen," of how such factors structure "regimes" (contrast with Gramsci's concept of political education and hegemony, what it means for a leadership to have a hegemonic vocation, and on what the durability of regimes turns), of the "three waves of modernity," and his privileging of the early modern era as a historical and moral watershed (contrast Marx's version of the same idea, and modernization theory's - and both of their emphases on the even greater watershed of the transition to full industrial society), are more interesting than they're being given credit for by critics.
It may well be true that Drury conflates the ideas of Strauss himself with those of the Straussians in power today -- or rather, that she grants that the neocon reception of Strauss's ideas is in fact the truest, most faithful (if not the only possible) interpretation of Strauss's ideas. This hermemenutic strategy is alas quite common: the actual writings of people who found of "schools of thought" tend to be highly complex, and often ambiguous and even opaque; typically these founders provide scant (if tantalizing) suggestions as to how to apply these ideas in practice. Precisely this open-endedness is what provides the latitude for followers to expand and develop the master's ideas; inevitably these expansions and developments can be legitimately seen as either extensions, or perversions, or both.
Given this extremely common phenomenon, intellectual historians must struggle mightily to determine clearly what was original to the master, and what was, for good or ill, added and lost in the master's reception among the followers. The historiography surrounding Marx and his followers provide the locus classicus for this phenomenon: was Engels the true intellectual heir of Marx, or did he pervert the man's intent? Lenin? Mao? (Vast literatures were once devoted to these debates, almost all of which is unreadable today.)
With this in mind, it seems to me that as a matter of intellectual historiography, even if Drury's work provides only a limited view of the inner possibilities of Strauss's thought, she's still done an admirable job is providing an explanation for why Strauss's ideas have proven so seductive to people who want to pursue the neocon political agenda; in short, she's unpacked the sotto voce neocon interpretation of Strauss.
Before I proceed, let me note that saying this does not imply that we can blame old Leo straightforwardly for the Iraq debacle. A crucial methodological point is that the influence of Straussian ideas on the neocons tells us more about the psychology of the neocons than it does about the inner meaning of Strauss's ideas themselves. Let me explain.
As much as intellectuals may learn from the work of great forebears, intellectuals (like other people) also "select" their influences as a way to put structure around pre-rational beliefs (or psychological conditions). There's no such thing as an intellectual tabula rasa: like everyone else, intellectuals start with a set of preconceived, fundamental intuitions. As they read to explore the nature of their intuitions and sentiments (this process of reading is what makes them intellectuals), they naturally glom onto intellectuals and ideas that help to justify their a priori intuitions; in short, much of what intellectuals do as they read is not seek out new ideas, but rather quest for "a usable past." One could perhaps describe this process as one of "inductive influence."
Consider the typical path most people underwent in becoming intellectual Marxists. Most people started with an intuitive revulsion at an economic system which allowed a handful of people to enrich themselves while destroying age-old communities and lifeways; then they read Marx and said, "Ah ha! This explains exactly what I've always intuited but never understand!" This kind of "inductive" pattern of intellectual influence is, I believe, far more common than "conversion experiences," whereby someone reads an author and changes his mind about something fundamental.
Let me hasten to add that this is not an anti-intellectual argument that all intellectuals do is provide rationalizations for prejudices. Certainly intellectuals do end up sometimes in that unfortunate role, but more commonly (and again, Marx is paradigmatic in this sense), intellectuals can consolidate and bring into a coherent form set of intuitions which otherwise remain ill-formed and thus unactionable. Very rare is the intellectual (Nietzsche?) who truly breaks the mold and produces something wholly original, rather than building and aggregating ideas that other authors put forth in vaguely-formed ways.
Finally, back to Strauss, and whether or not the neocons have in any significant sense "misappropriated" his ideas. "Applications" by followers of the high-order syntheses and complex analyses of a master inevitably involve interpretation and (to purists, disappointing) compromises. So how much can Strauss be held responsible for, say, Paul Wolfowitz's ideas, or more narrowly, for the invasion of Iraq?
To answer this question, it's worth recollecting what Derrida once said about Nietzsche's "responsibility" for Nazism. He said that while Nazism was a falsification of Nietzsche's purposes and essence, it is also true that some authors are more "available" to pernicious falsification than others. It's hard to imagine, Derrida pointed out, J. S. Mill being invoked to justify political atrocity quite as easily as Nietzsche. (Then again, the Indians might disagree.) Nietzsche had to be held to account, Derrida felt, for producing an oeuvre that at moments exalted violence, power, elitism, hatred, madness and a castigation of any sense of limits or humility -- and the fact that other moments of his thought provided ample grounds for a more humanistic reading does not absolve Nietzsche of responsibility for producing passages which, taken out of their deep philosophical context, can easily be seen as provocations to a very dangerous politics.