By "fighting the last war," Bale and Bar-On mean (to simplify a bit) that critics of the radical Right focus on Nazism when the real problem is Islamism. Old-style right-wingers—"tiny fringe groups of actual extremists, such as revolutionary neo-fascists and neo-Nazis, armed Klansmen, Christian Identity adherents, Sovereign Citizens, violent skinheads, virulent antisemites, neo-Confederates, racial Odinists, and unaligned white supremacists"—are marginal figures that cannot seriously challenge the existing order. That said, they make a convenient punching bag for the "globalist elites, their media mouthpieces, and the left" who prefer, for reasons of identity politics, to ignore the Islamist elephant in the room. (Also, those actual extremists lack a lobby.)
Bale and Bar-On (confusingly affiliated with, respectively, similarly-named but unrelated institutions, the Middlebury Institute of International Studies at Monterey and the Tecnológico de Monterrey) set the tone of the book in their acknowledgements where they thank colleagues and friends in the abstract but provide no specifics because they "felt that it was more prudent not to name others who have offered us assistance in various ways." This fits Fighting the Last War's sense of siege due to what the authors call
a concerted effort by political and economic elites, the mainstream media, academics, left-wing watchdog organizations, and the new Big Tech oligarchs to delegitimize and demonize virtually every opponent of the currently regnant Western ideology of "progressive" globalism, no matter where those opponents actually lie on the political spectrum.
Accordingly, those now accused of being on the radical Right include advocates of centrist notions such as
patriotism, civic nationalism, preserving national sovereignty, limited government, free speech, evaluating individuals on the basis of their own characters rather than their race and gender, maintaining the distinctive features of particular national communities, or respecting certain tried and true social customs, traditions, or institutions.
As for Islamists, they are the true "radical right-wingers" who "are not only theocratic, totalitarian, and violent (in the case of jihadists) but also imperialists whose ultimate aim is to conquer the entire world for Islam." This author has doubts about labeling Islamism as a right-wing phenomenon; that said, the time has come to heed Bale and Bar-On's excellent analysis: stop fighting the last war and engage in the current one.