Trudeau died in 1991, after something of a checkered career. He was a genuine hero of the Korean War and Chief of Army Intelligence 1953-5, when he shot himself in the foot by making an unsanctioned approach to Adenauer, got across Allen Dulles, and was shipped to the Far East. There are (parts of) a Trudeau memoir on Google Books, and a Goggle on "general trudeau intelligence" will get that and (parts of) a book that covers the Adenauer affair, entitled "Partners at the Creation." (The URLs for these things are insane.) The problem with others not speaking up in support of Corso is that by 1997, when the book came out, most of those with the rank to be in a position to know were probably dead.
Judging by Strom Thurmond's reaction, what Corso did was to write his actual memoirs, find that no one wanted to publish them, and then punch them up with a lot of war stories about mysterious items and the Roswell crash. Corso's son may have had something to do with this; he seems to have been determined to make a buck off Dad, and probably had heard those war stories before. (And allegedly messed up a Hollywood movie deal.) Thurmond wrote an introduction to the book, and would say that he'd written it for that Roswell-free memoir and make the publishers remove it from later editions.
I might point out that the book begins with an account of the Roswell crash, supposedly derived from the Secret Files, that trashes the testimony of just about every major witness to the case except "Steve Arnold," who is probably one of the avatars of Frank Kauffman. Kauffman was taken to be a really pivotal witness by Randle and Schmitt, at least, and in a sorry example of just how well the Roswell case has been investigated, his story (which appeared in three or six variations, I forget) depended on his discharge papers, which he'd never let investigators examine closely while he was alive. Then he died, and -- who'd a thunk it? -- they turned out to be crude forgeries.
Corso was a technological blindworm -- he gets a whole lot of things he should have known wrong -- and thus an odd choice for an R&D man, and his technology transfer claims are bunk; most of the examples he gives were being worked on, and even worked out (patents for integrated circuits were issued in 1959) before he ever showed up with his "Roswell debris." Key developments in some fields (notably fiber optics) were made outside the US. The whole R&D episode of his career has the flavor of Trudeau creating a niche for Corso and trying to get him promoted to full colonel (the 90 days for which he headed up Foreign Technology were just enough to get him rated in the position), so that he could avoid being retired on "up or out," or maybe just retire in a nicer pay grade.
Since the technology transfer claims are the heart of the book, I can't see a reason to put any stock in anything Corso says that can't be verified from other sources, not counting the plain old mistakes. I don't believe he was the secret pivot man of the Cuban missile crisis or that he once waved his pistol around the office of a CIA officer, either. I don't think he saw an alien body from Roswell and I don't think he ever saw any secret reports on that case; his story of the crash sounds a lot more as if it came from Roswell witnesses accessible in the 90s. All in all it's part of a depressing latter-day trend in UFOlogy: It's a hoax, and it's not even a very good one. Nonetheless it gets some traction because Corso's an "insider" and he's propping up both Roswell and the government cover-up theory.