Visiting Hiroshima last week, President Obama expressed the wish that in the future no community would ever have to suffer the horrors inflicted on that city in 1945, and moreover, that the bombing should never be forgotten. Those sentiments were obvious and unexceptionable. Much more debatable, though, was his restatement of his desire to see a world free of nuclear weapons. If expressed as a general platitude, that is fine, but if it represents any kind of serious strategy or policy goal, it is dangerous to the point of insanity. Hard though this may be to hear, we desperately need our nukes.

The year 1945 marked the beginning of an era of unprecedented peace and security in Europe, which with brief interruptions has continued until the present day. That glorious new age did not happen because of a sudden moral improvement, or the rise of the European unification movement, or any ideological tilt. It happened because both superpowers knew that if either broke the security balance within Europe, the result would be a catastrophic nuclear war that would have annihilated Europe, and deeply damaged the homelands of both the U.S. and the Soviet Union. That balance of terror removed the vast advantage that the Soviets had from their enormous superiority in land forces. That seventy years of peace is founded on the existence of large numbers of nuclear arms.

If we try to rewrite the history of Europe without assuming the existence of those weapons, it is scarcely possible to imagine such an enduring peace, except on the basis of the permanent total mobilization of all European powers, as well as the nations of the Anglosphere. Such mass mobilization seems bizarre to anyone brought up in our own nuclear world, but the idea was a reality from the Napoleonic Wars onwards. The normal calculation was that for every million people in a nation’s population, you could sustain two divisions. Only a society spoiled by the security of Mutual Assured Destruction could have forgotten such brutal mathematics.

A future world without nuclear weapons would have to return to mass mobilization and universal conscription in order to counterbalance the advantages of great continental states unafraid to venture “boots on the ground” in their many millions—China obviously, but also Russia, Pakistan, and India, among others. Fortunately, the modern U.S. would have the blessing of all the women who would happily agree to be drafted to serve alongside the millions of soldiers and sailors the nation would need to keep in uniform to maintain its security. How does a 12 million strong standing U.S. army sound?

Not, of course, that all future wars would necessarily be slogging matches between infantry, or trench warfare. Even without actually using nuclear weapons, we can see clearly how the world would have developed after 1945 without that overwhelming deterrent. By the end of the Second World War, the U.S. and Britain had perfected the art of destroying cities by air raids involving thousands of aircraft, using firebombs and napalm. Even in those early years, they were inflicting death-tolls running into the tens or hundreds of thousands. Those technologies would presumably be much more advanced today, so that any non-nuclear war could be incredibly destructive, and would claim many millions of lives.

During the height of the Cold War, the British also toyed with the idea of quite impressive non-nuclear deterrents. By the early 1950s, the cutting edge of their military thinking was Operation Cauldron, which sought deterrents based on biological warfare. The most promising components in this witches’ brew included brucellosis, tularaemia, and also pneumatic and bubonic plague. We know about these efforts today because of the truly chilling 1952 incident in which the trawler Carella inadvertently wandered into British test waters and was exposed to some of these hellish agents. Rather than quarantining the sailors, or even notifying them of the dangers they faced, the military began a covert surveillance to track their health and see whether they might spread infections when they reached British ports. The Carella scandal has shed light on the larger world of Cauldron.

That was 1952. Presumably the range of catastrophic biological agents available to even small powers today is vastly greater, and even more lethal.

So exactly what part of the nuclear-free world are we pining for? The constant mobilization and militarization of all major societies? The investment in massed bomber fleets to charbroil the cities of any potential enemies? Or the total dependence on biological deterrence, with the President’s finger constantly on the bubonic trigger? Dare I say that none of this actually sounds attractive? The main difference between that hypothetical world and the nuclear-armed world we know is that those alternative weapons would have stood a far greater chance of actually being used.

In 1970, the British heavy rock band, the Groundhogs, issued an album with the seemingly appalling title Thank Christ for the Bomb. Today, we might imagine this as shock for shock’s sake, like later punk numbers, but it was anything but that. The thoughtful lyrics of the title song stated a simple thesis, namely that the twentieth century had witnessed two hugely damaging wars that had killed millions, but that since 1945, the advanced nations at least had avoided any recurrence of such a fate. The reason for that sea change, said the Groundhogs, was quite clear, which is why they exclaimed, “Thank Christ for the bomb.” That argument demands examination, and respect.

If President Obama wants to reduce the number of nuclear weapons among all powers, he should be encouraged. If he wants to see arsenals of at most a few hundred warheads for even the greatest nations, with correspondingly smaller hoards for smaller nations, all well and good. If, though, he seriously contemplates a world without nuclear weapons, then he is utterly and perilously ignorant of modern history.

Philip Jenkins is the author of The Many Faces of Christ: The Thousand Year Story of the Survival and Influence of the Lost Gospels. He is distinguished professor of history at Baylor University and serves as co-director for the Program on Historical Studies of Religion in the Institute for Studies of Religion.