Though, of course, Alfred Hitchcock didn't fight in World War II, he did see hitherto hard-to-find footage of the atrocities in the concentration camps. He also had first-hand experience of WWI, having been in London at the time of the German air raids on that city. In fact, he cites that period as the first time he experienced real fear. In his essay, “Enjoyment of Fear,” he compares suspense and terror with the difference between a buzz bomb and a German V-2 bomb. The buzz bomb made a buzzing noise, but then right before it was supposed to land, the buzzing motor cut off. That interval when it went silent created suspense, because victims knew it was nearby, but they didn't know if it would hit their building. That's suspense. But the noiseless approach of the much more destructive V-2 bomb had a surprise effect, which he called terror.
In effect, Hitchcock was comparing his movies to a Nazi aerial bombardment! Outrageous, when you think about it. What's even more amazing is that he wrote that article for Good Housekeeping magazine, a mere four years after WWII had ended! I mean, can you see Coppola comparing Apocalypse Now to a napalm attack? Maybe. But would it appear in Good Housekeeping, circa 1982? Doubt he could pull that off. But Hitch could get away with such language because he was so skillful at the use of humor as tool for deniability. (c.f Rope: "You don't really believe that there's a superior few who have the right to commit murder?" "I most certainly do!" Tongue-in-cheek, or not?) Hitch's use of that analogy speaks, I think, to his approach to film, that he used the medium to terrorize audiences. Literally. I think he saw his films as acts of war or terrorism. Sabotage is his testament to that—remind me to explain what I mean by that in another post.
Perhaps, then, Rope, Vertigo, NxNW, Torn Curtain, Topaz, The Birds etc. are all of a piece in that they all use the psychology of war as a dramaturgical and a cinematic device. Hitch's mastery and mischievousness are well documented. But I think his radicalism has, at this point, been, as G.W. Bush would say, misunderestimated. I propose that the psychology of war is the theoretical substrate of most, if not almost all, of Hitch's films.