How To Dismantle A Country

Let’s say it’s the 1970s and you’re a foreign power of one sort or another – Soviet Union, China, Arab oil interests, secret cabal of billionaires, whatever – and you want to dominate the world. But the US is in your way…
Let’s say you do a comprehensive analysis of all the things that make the US a world power (for better or worse). Let’s say you develop a plan to infiltrate, undermine, weaken, fracture and ultimately dismantle each the institutions that made America so strong.

Looking back today, can anyone offer anything that could have been more effective at accomplishing this plan than funding America’s conservative movement?