He alone threatens the international balance and relations between the great powers: the Chinese arms dealer Li Fangwei, also known as Karl Lee, is said to have enabled Iran to build up an impressive arsenal of missiles. Actively sought by the FBI for several decades, the man is a veritable ghost: intelligence only has a photo and a passport number. Born in 1972 in the far northeast of China, Karl Lee began to attract the attention of the U.S. Secret Service in the early 2000s by making suspicious financial transactions. Washington quickly became aware of the extent of his activities.