On September 22, 2009, China made its last-minute appeal of the August 12, 2009 World Trade Organization ("WTO") panel ruling on Chinese publication and entertainment distributions restrictions, invoking "public morals" as a defense. The case was brought to the WTO by the United States in April 2007, attracting extensive attention from both sides. The appeal again escalates the trade tensions between the two partners, following the United States' imposition of tariffs on tires from China and appeal of another WTO ruling on China's protection and enforcement of intellectual property rights.