Nuclear warfare is likely to be quite different from past conflicts. The great concentration of firepower which a nuclear weapon represents makes it possible to attack on enemy anywhere, at very short notice. This is true no matter what the particular target is, whether one is trying to attack the planes, ships, tanks, or troop concentrations of an enemy. The great mobility of nuclear firepower makes it highly probable that the nuclear conflict will be short. What the factory produces during this conflict will not affect the outcome of the fighting. The only weapons on which anyone can rely are the weapons which are already stockpiled. Therefore, it will be militarily useless to bomb factories. The same fact of mobility also implies that no great flow of war material will need to be maintained. Practically all movement can be executed by light and fast methods, by planes, submarines, and small battle groups. Under these conditions the cities will lose their importance as centers of transportation. The only purpose in bombing cities will be to spread terror among the enemy. This was rarely done in past wars. In fact, terror is self-defeating because it provokes retaliation from the other side. We believe that the role of nuclear weapons in a future war is by no means the killing of millions of civilians. It is rather to stop the armed forces of an aggressor. This is not easy to do because it requires not only nuclear weapons, but very special kinds of nuclear weapons which are hard to develop and harder to perfect. But with proper experimentation and proper planning the defensive use of nuclear weapons is possible. The idea of tactical nuclear weapons is not new. The possibility of using nuclear explosives in small wars has been frequently discussed. What kind of weapons do we need in order to fight these small wars and to defend the freedom of people wherever such defense becomes necessary? It has often been suggested that in small wars, small weapons will be used, while big weapons are appropriate for big wars. Such a statement is much too simple and has no relation to reality. In every case the right kind of weapon is the one which performs the job of stopping the enemy’s armed forces without inflicting unnecessary loss on the innocent bystander. For this purpose we need a great number of weapons which are adaptable to specific purposes, which are easy to transport and easy to deliver, and give rise to the kind of effect which the situation requires. For instance, a nuclear weapon may be carried by a fighter plane and used to shoot down an attacking bomber. Since the carrying capacity of the fighter plane is severely limited, the weapon for this purpose must be small and light. A major objective of the test program is to develop such purely defensive weapons.