North Korea began producing chemical weapons in the 1980s and currently holds a stockpile of an estimated 2,500 to 5,000 tons of chemical weapons. Sources indicate that North Korea is capable of cultivating and producing various types of biological agents such as anthrax, smallpox, and pest on its own. | War sustainment Capability | Despite the ongoing economic crisis, North Korea is channeling resources into developing the defense industry as a top priority in order to maintain its war sustainment capability. North Korea has an estimated 300 armament factories, and civilian factories designated for transition to armament production are capable of shifting to a wartime mobilization mode in a short period of time. With most of its war supplies stored in tunnel storage facilities, North Korea is assessed to possess a stockpile of war supplies that can last one to three months. However, without external assistance, North Korea’s ability to sustain a prolonged war is likely to be limited. 34 Chapter 1 Changes and Challenges in the Security environment