Why is China building launch pads near its nuclear missile silos, and what do satellite images reveal about sites with over 80 launch pads?

Satellite images reveal that China is constructing a vast network of military infrastructure in its north-western deserts, including more than 80 potential launch pads and fortified complexes. The expansion appears to be aimed at enhancing China's ability to launch a retaliatory nuclear strike and improving the survivability of its land-based nuclear forces.