I don't have a detailed analysis or anything, but I always feel that the prior generations of imperialists, especially the immediate post-WWII, had a vision for the planet - total capitalist hegemony under the direction of the US government - and worked hard on a plan to implement it. Those planners were practical, intelligent, and willing to get their hands dirty. They projected one image of themselves - global liberators fighting against tyranny - while knowingly advancing their project in favor of the capitalists. The current generation, who grew up underneath them but not nestled in those highest places of power, bought into the image projected without understanding the reality of its operation or how it was established. They swallowed the cognitive dissonance and believed it entirely, so now they the simple act of military violence as synonymous with "freedom". They have no grasp of how the empire actually operates, they aren't advanced through anything like a meritocracy, and they can't distinguish between their own propaganda and the truth.