It was discovered, during inspections and testing conducted by the International Atomic Energy Agency (IAEA), that Taiwan had been working on creating weapons grade nuclear materials as far back as the 1980s. The Taiwanese government agreed to voluntary extra controls on the country's peaceful nuclear program in order to reassure the world that it was not building nuclear weapons. But the IAEA inspections have proved that Taiwan has been laying the ground work for a nuclear weapons program for at least two decades. Nuclear weapons would be the ultimate weapon to prevent a Chinese invasion.