Hiroshima Peace Memorial,

Hiroshima Peace Memorial, also called the Atomic Bomb Dome, is one of the few downtown buildings to survive the bombing in 1945. It is preserved as part of the city's peace park.

Frank “Fg2” Gualtieri/Wikimedia Commons

We don't do enough thinking about catastrophe, so let's pause to note that everything on our national political stage -- tax reform, immigration, health care, the Mueller investigation -- and in our private lives, for that matter, occurs against two apocalyptic backdrops: climate change and nuclear war.

That's too much to think about in 700 words, so let's allow climate change to simmer on the back burner for a while. Despite already catastrophic effects, we're doing very little about it, anyway; on the contrary, we've elected national leadership that doesn't take it seriously.

So let's consider instead the possibility of nuclear war:

The 1962 Cuban Missile Crisis got our attention, and for a decade or two we lived with the reality that nuclear destruction was as few as 30 minutes away. We built fallout shelters, studied ways to protect ourselves from radiation and held civil defense drills.

Then we got used to the idea and settled into a grim nuclear standoff with other nuclear nations; the notion of nuclear annihilation became as abstract and distant -- and as easily ignorable -- as climate change.

We even made successful efforts at limiting nuclear proliferation and at reducing standing nuclear arsenals.

But with Iran, North Korea and a U.S. president more inclined toward belligerence than diplomacy, things have changed: nuclear is back.

Current conditions are reminiscent of the world of 1913, just prior to the start of the First World War:

The Great War didn't have a proximate cause, and historians still puzzle over why it happened at all. How could such a cataclysmic world-wide event be triggered by an isolated assassination in Sarajevo in 1914?

The answer resides in the tensions and rivalries among the great international powers of the day and in their response to them, which was to prepare for war. For example, in 1900 Germany decided to build a fleet to match Britain's Royal Navy, and by 1906 a full-fledged race for battleship superiority was underway.

Similarly, France extended the terms of service of its conscripts in order to match the size of Germany's growing army. In short, by 1913 armies and weapons had taken on a life of their own that threatened the power of national leaders and diplomats to control them. Because the European powers were so well prepared for war, war had become almost inevitable. The assassination of Archduke Ferdinand was merely the incidental trigger that ignited the conflagration.

Further, in 1913 war was a matter of horses and swords and single-shot, bolt-action rifles. Certainly, soldiers got hurt and many died, but Europe didn't have the collective imagination to envision the devastation of a modern war fought with modern weapons. Few could have predicted 40 million casualties in just four years.

We suffer from both of these conditions today: We've never really absorbed the stark lessons of Hiroshima and Nagasaki, and we've failed to extrapolate the devastation of the two comparatively modest nuclear weapons discharged in 1945 to a significant exchange of today's much more powerful weapons.

Because the aftermath of a real nuclear war is unthinkable, we've largely refused to think about it.

Further, the weapons themselves threaten our capacity to control them. Nuclear weapons are precarious, as indicated by the recent panic in Honolulu when a defense drill got out of hand. And while we might hope that the use of nuclear weapons could be constrained by rationality, somehow in our country we've allowed the so-called nuclear football to fall into the hands of a man who is characterized by emotion, insecurity, impulse and bluster. And then there's Kim Jong-un.

One other factor works against us, just as it did in 1913: Next year's Pentagon budget will be $716 billion, the largest ever. Weapons demand to be used. We've never invented a weapon that we've declined to use. All of this implies that a nuclear war is inevitable, and the ensuing calamity will be unimaginable. The only silver lining is that the devastation of climate change will fade into insignificance.

John M. Crisp, an op-ed columnist for Tribune News Service, lives in Georgetown, Texas.