Artistic expression censorship in the US

Those countries directly affected by these events saw the cutting off of artistic expression or at least a severe censorship. It could be as dramatic as the imprisonment of writers for publishing critical writings, but it could also be due to the inability to get work out of the country or even to obtain supplies. In countries in the West, where there was not so much governmental control, you still saw quite a bit of societal censorship of work thought to be unpatriotic or overly critical. We saw this even in the last few years with the reaction to the Dixie Chicks criticism of the Iraqi war. Explain.