North Korea will open with artillery and rocket fire from positions on the North slopes of the mountains just across the border. The North has the world’s largest artillery force with 10,000 pieces in their arsenal. The bulk of these forces are at the border, with much of the rest around Pyongyang and near Nampo, the site of their electricity-producing dam. It is likely that the South Korean capital of Seoul, just 35 miles from the border, would be the first target and would be devastated in the opening salvos.
With the artillery on the North side, hidden in the mountain, there would be little warning of an attack and US and South Korean air forces would have trouble penetrating the North Korean air defenses. Air operations would be tricky because the North keeps tight interlocking lines of antiaircraft guns and surface-to-air missile systems. Pyongyang itself is a “fortress.”
North Korean special operations forces would be inserted via submarines along both coasts and through tunnels dug under the DMZ (many have been found in previous years). Latest reports suggest they would use special operations to deliver chemical attacks and dirty bombs in the South. They also have significant biological weapons facilities in the North that they tested on their own citizens.
They would also activate sleeper agents in the South to direct missile and artillery fire. South Korean intelligence estimates up to 200,000 special operators in the North Korean military, trained to fight Taliban-like insurgencies.
The US air assets in the area will establish air superiority over the region, destroy air defenses, attempt to take out the artillery and missile batteries, and then destroy Northern command and control elements. After that, allied airpower will target infrastructure like bridges and roads, especially the unification highway linking the capital at Pyongyang with the border, to keep Northern forces from being able to move effectively inside their own country.