modern weaponry advances faster than any other branch of technology. Already the bombs dropped on Hiroshima and Nagasaki have joined the pike and the catapult as military museum pieces. But the advance (if one may so describe it) has not been entirely, or even mainly, in the direction of what Congressional Committees call “getting a bigger bang for a buck”. On the contrary, once the 20-megaton H Bomb had been devised, the trend in nuclear weapons technology took the opposite direction. Most tests during the last five years have been of weapons with nuclear warheads of decreasing force. In 1958, for example, the Americans fired an atomic shell with the force of only 6 tons of TNT.

Since then, all three American services have added a bewildering assortment of low-yield atomic weapons to their armouries. And their units in NATO—along with those of their allies—are being equipped with them and trained in their use. These are the so-called tactical nuclear weapons, ostensibly designed for use against troops on the battlefield. Most of them are shortrange missiles.

The Honest John missile, for instance, is an unguided field artillery weapon with a range of about 16 miles. Its brother, Little John, is lighter and faster, with a range of only 10 miles. Both can be fitted with nuclear warheads of various yields. But, as the missile men themselves say, if you can use them, they’re obsolete. Honest John and Little John are being superseded by Lacrosse, a radio-guided missile with a range of about 20miles. The short-range Shillelagh is not yet operational, but it should be within 12 months.

The most ominous development of all, however, has produced the Davy Crockett. This is a missile that can be fired from a bazooka-like contraption and carries a nuclear warhead 2 miles. Nuclear warheads, in fact, can now be fitted to almost any size of projectile. These, in turn, can be fired from almost any kind of “conventional” weapon, from mortars to the 8-in. howitzer. The entire armoury of a modern army can be made nuclear by a few simple adjustments. Only the rifle and the pistol remain immutably conventional at the moment.

Yet even these weapons, it seems, are due for the same transformation as the others. For what may be called the Second Law of nuclear weaponry applies here. This is: if you can imagine it, it will be made.