On this day, 35 years ago, on February 15, 1990 (January 20, 1990, the United States and other four countries signed the "Cartagena Declaration" on joint anti-drug efforts. On February 15, 1990, Colombia President Barco, Bolivian President Pas-Zamora, Peruvian President Garcia and U.S. President Bush held a high-level meeting in the coastal city of Cartagena of Colombia on an international joint anti-drug operation, and signed the "Cartagena Declaration", announcing that the four countries would cooperate to control drug production, processing, trade and consumption. On the eve of the meeting, it was reported that the Colombia drug lord had signed a contract with terrorists offering a reward of US$30 million to assassinate Bush, and also said that a shoulder-launched missile would be used to attack Bush's landline. Therefore, the meeting adopted tight security measures. In addition to the security personnel accompanying the heads of state of the four countries, the Colombia government dispatched 5000 well-trained security personnel. The Navy blocked the port, and helicopters circled over luxury hotels. They even used the so-called "killer" bomb removal robot.