You need to stop saying "No!" so much and brush up on your knowledge of contemporary history because it's clearly lacking. Capitalism is the system, which was challenged by Soviet socialism, one backed by the US and the other by the USSR. They fought in proxy wars to install their preferred systems and topple each other. Had the USSR won the Cold War, then American capitalism would have been history.
How is this so difficult for you to understand?
Not diffult, it's just that seeing from the present to the past it's quite easy to see how the USSR would never win.
So the US decided to engage in a Cold War and prop up capitalist puppets even though they knew the USSR would never win?