Loose nuclear weapons in Pakistan are, or should be, keeping military planners up at night, especially those in China, Russia, India, and the U.S. Even a slight chance that some of the 50 to 100 weapons in Pakistan’s arsenal could fall into the hands of radicals Islamists is a chance that the world cannot afford to take.

Loose nuclear weapons are not exactly a new problem, and it is not one confined to basket-case states like Pakistan. Even highly developed countries sometimes have difficulty keeping their weapons secure. Just this year, the U.S. lost control of some of its nuclear arms for a period of hours.

A dramatic and little known case occurred in France in the spring of 1961. The story is told in “The Risks of Spreading Weapons: A Historical Case” by D. G. Brennan in the 1968, Volume 1 edition of a relatively obscure journal, Arms Control and Disarmament.

In mid-April 1961, the French were preparing for their fourth nuclear weapon test (three had taken place in 1960 at their Sahara test site near Reggan in central Algeria. On 22 April, General Maurice Challe, former Commander-in-Chief of French forces in Algeria, initiated the rebellion in Algeria that came to be known as “The Revolt of the Generals.” The French scientists at the test site were immediately nervous about the security of their incipient nuclear explosive, and began hurried preparations to detonate the device, so as to remove it from any possibility of seizure. . . . [T]he French general in charge of the test site, while not participating in the revolt, was a friend of General Challe, and he did not want the device detonated. However the scientists at the site got authorization from Paris to set if off anyway. They exploded the device early on the morning of April 25, 3 days after the start of the revolt.

It was set off with hastily-improvised and incomplete detonation arrangements, and because of this, it gave a very low yield of less than one kiloton. (The French Government communiqué announcing the shot described it as of “weak power.”) Observers in various countries other than France who became aware of the nature and yield of the explosion thought the test a failure, and I t was often described openly as a “fizzle.” However…the explosive was “optimized” to be only the fastest way of unambiguously getting rid of the fissile material on hand for the weapon, not to provide high yield. For this objective, the “test” was of course a complete success.

It could have been important that it was a success, in this sense. The rebels were already making claims to have taken over control of the whole of Algeria. Although this claim proved false as far as the test site was concerned, it is highly probable they would have made major attempts to seize it if they known an incipient nuclear explosive remained there.

While it is difficult to see how possession of that explosive by the rebels would have altered the outcome of the rebellions (which collapsed the next day), it is not difficult toe believe they might have attempted to use it to blackmail the government, and it is even possible to conceive that some fanatics might have used it destructively as a last act of bitter revenge.

All is not well that ends well. If this kind of frightening near-miss scenario played out in developed country like France, we do have ample reason to stay awake at night worrying about the fate of the Pakistani nuclear arsenal.