Technology changes things, sure. The question is, how do you recognize the early signs of change before they become catastrophic? I spend most of my days working on that question in academia, but what about our armed forces? Noah Shachtman regularly covers that issue in DefenseTech:
Like a lot of other sage observers, Naval Postgraduate School professor John Arquilla isn’t nuts about the idea of spending a ton on Cold War-style weapons systems when we’re supposed to be fighting terrorists and insurgents. But Arquilla is one of the first military analysts I’ve heard say that “the Pentagon’s big platforms [aren't] merely the wrong weapon systems to fight present and future wars, but [are] actually likely to bring defeat.”
The superiority of aircraft made huge battleships a liability just before World War II. The climax of Top Gun pretty much centered on the vulnerability of our all our ships — including aircraft carriers — to missile attack (BTW, those Exocet missiles now sport ranges as high as 180km). But these are just a few examples of the general problem. Of course, the Navy isn’t the only force with big, Cold-War iron. There’s more, including some good quotes at DefenseTech.