Anti-Americanism is hostility towards the people, policies and culture of United States of America.
Many Islamist regimes are noted for their anti-American sentiments- often disguised as criticism of the War on Terror. Those with anti-American sentiments often lack the liberty celebrated in America and therefore hate America because of the freedoms available to the American people, and many are liberals who believe that other nations are equal to or beyond America in their achievements.
"Anti-Americanism is not only the world’s most pernicious and ubiquitous ideology — it is also the most tenacious. In fact, it has taken on some aspects of a religion." 
"Anti-Americanism is the prevailing disease of intellectuals today."