To fight a war, one must concentrate forces to destroy the enemy's effective strength.
(January 28, 1969)

A large part of the existing fortifications may be useless once fighting begins, because they do not follow this principle in warfare.
Wasn't the Maginot Line breached? It didn’t serve much purpose. Many troops got bogged down there, and mobile forces were reduced.

Some people have never paid attention to enemy airborne and air raids. Warfare today is three-dimensional; the enemy will strike your rear areas, so when building field works, one must also prepare against airborne landings and air raids.

Field works might be of some use, or they might not be of much use. Some field works can hold off the enemy for one or two weeks, and some can hold out a bit longer—maybe for half a year. But what do you do in the second half of the year? They still have to be built. There are two kinds of field works: one kind provides a temporary block, and the other can hold out a bit longer. Most of the rest are largely useless. The enemy can come from anywhere; why would they choose to dash themselves against a nail? For instance, when the Soviet Union sent troops into the Northeast, the force that came by way of Baichengzi met no resistance whatsoever; the force advancing along the eastern route, when they reached the vicinity of Mudanjiang, suffered a setback.

We have never fought by simply holding the line. If the enemy wants to come, let them come; if they want to go to some place, let them go. In the Fifth Counter-Campaign against "Encirclement and Suppression," we tried to hold the line, and it cost us the entire Central Soviet Area.

If we build too many field works, most of them will prove useless in the future and will inevitably have to be abandoned. You might guard the field works for half a year and the enemy never comes, but in the end, they come somewhere else. You position your main force there and wait half a year or a year, and if the enemy does not come, what do you do? A hero finds no place to display his prowess.

In the south, at least there is grass; in the north, there is none. But over seven or eight years, some field works might just...
[I] This is a summary of points made by Mao Zedong while listening to a report from the Office of the Military Commission of the CPC Central Committee.