Mr Lewis is an Islamist. He truly has boundless knowledge and admiration for Islam, but he is an honest man.
He is loath to make statements like that one (I have never heard one on tape). I have read most of his books.
Of course, historically, he is spot on, but has never "lost it" that way in print, that I know of.
Islam, as a combination culture/political system/imperialist movement is truly hopeless. It never gets wiser, just finds better weapons.
In that sense, I hope you're right that fundamentalist Islam is hopeless in a historical sense, rather than us as a function of our refusal to recognize the nature of our enemy. For all the yapping about the threat of transborder multiculturalism, not many recognize that fundamentalist Islam is it in it's most virulent form.