American culture or what is probably a lack thereof, is probably the most powerful weapon in the US arsenal. Also the most effective-the fall of the Soviet Union can be attributed, at least in part, to the relentless propagandist projection of the west as champions of freedom. While western capitalist countries were accusing the Soviets of brain-washing and oppression, they were guilty of the same.
American is a melting pot of cultures but primarily, it is a safe haven for rebels and misfits. There was a thread in the politics forum which questioned the UK's asylum rules. This is just one example of what a government is willing to do(endanger its own citizens) for the single ludicrous purpose of supporting capitalist policies.
Of course American culture is strong, as I said before. With technology and entertainment a monopoly of the USA, no other country can compete. To do so would be foolhardy-infringing the first rule of logic NOT to complicate but to simplify. It is expected and shyly accepted-the intel chip and McDonald's.
Having said that, there is always an undercurrent of capitalistic design, of freedom, of unbridled individualism in American culture. It encourages rebellion, disobedience and mutiny. Most other cultures succumb to this heady mix of selfishness and indulgence, there are some, like the Muslim world which is the sine qua non of hedonism, ergo the antithesis of American culture.
Therein lies the problem of American culture-it's strength is its weakness.