There's a reason they were selling a pretty talk stack of these for $2 a pop at a local salvage market. What should be a good story - the complicated relationship between France and the United States nee the 13 North American colonies in the context of Great Powers relationships - is completely botched by poor historical research and some of the most hackneyed writing I've seen.
Sure, Unger has the facts more or less straight, and there's no doubt that French support for the American Revolution was motivated less by love for freedom and democracy (absolute monarchs surely harbor these sentiments, no?) and more by the worldwide game of Empire in which they were competing (and losing) to Britannia. The French monarchy was decadent, and they had every intention of trying to reassert the claims of Empire in the New World. Yes. But to jump from that to characterizing that as a "plot against America" - and more significantly, a plot against Americans - is in no way warranted by the research, and reducing French "anti-Americanism" (in itself a complicated phenomenon that goes beyond "they hate everything about us because...").
Even with the poor and unsystematic historical analysis, I would've given this book a chance, if just to familiarize with the point of view and how it's arrived at. But then I read this line in describing the French enthusiasm for the American cause in the early days of the Revolutionary War: "Unarmed American farmers had displayed more courage than kings, cried critics of the crown, and demonstrated the vulnerability of the vaunted English Army." There is, of course, no source cited for these "critics," but more significantly, no one would have characterized one of the sides in an armed conflict as "unarmed." There are other moments of titillating detail which serve to stoke anger at the French aristocracy (and nation) rather than to illuminate the narrative. Unger relies on a lazy use of cliched tropes, and makes no attempt to use them in interesting, or even in accurate kind of ways. His credibility is just dashed at this point, and I wasn't able to make it past page 90 before I felt like this was a complete waste of my time.
Don't even bother picking this up out of a free box.