The Clinton presidency from 1992 started with an executive order (128590) that linked renewal of China's MFN status with seven human rights conditions, including "preservation of Tibetan indigenous religion and culture" and "access to prisons for international human rights organisations"—Clinton reversed this position a year later. Other challenges to Sino-American relations in this decade included the investigations into Chinese nuclear espionage which produced the Cox Report, the persecution of Taiwanese-American scientist Wen Ho Lee for unproven allegations of espionage for the PRC, and the 1999 United States bombing of the Chinese embassy in Belgrade. But relations warmed after the September 2001 initiation by George W. Bush of the War on Terror.