China's Missiles Come Out of the Cave -SD-HQ

During the height of the Cold War, the world’s preeminent communist powers – the People’s Republic of China and the Soviet Union – were also at odds over differing political ideologies. With a willingness on both sides to escalate their conflict to war, the threat of nuclear catastrophe loomed larger than ever.

A very good educational video made by the Georgetown University, Washington DC, for the Arms Control Seminar, describing China's "Underground Great Wall" tunnel network, which plays an important role in China's nuclear deterrence capability by enabling China to have a survivable second strike ability, while simultaneously masking the true number of China's nuclear arsenal.

By 2011, the "Underground Great Wall" is reported to amass 3500 miles in total, hiding an estimated number of 2500 to 3000 nuclear warheads.

The "Underground Great Wall" also hides underground production/enrichment facilities and nuclear reactors for additional warhead production.

-https://www.belfercenter.org/publication/chinas-underground-great-wall-subterranean-ballistic-missiles