Every year in August, people take to the blogosphere to debate the morality of the U.S. nuclear bombings of Hiroshima and Nagasaki, which took place in August of 1945.

This year, physicist Tom Hartsfield has a piece on Real Clear Science in which he argues that dropping the bomb on these cities was the right thing to do.

He makes two arguments, neither of which works.


The Numbers Argument

Hartsfield’s first argument is that nuking Hiroshima and Nagasaki was morally justified on the grounds that it prevented higher numbers of casualties. He writes:

The two atomic bombs killed roughly 200,000. Japanese military officers estimated that as many as 20,000,000 Japanese would have lost their lives in defense of the Japanese mainland. America estimated its own deaths to number in the hundreds of thousands. Wounded would have been in the millions on both sides.

At first glance, Hartsfield’s numbers are impressive. Twenty million Japanese people alone would have died—as opposed to the 200,000 that the bomb killed? That’s a factor of 100! It’s such a large factor that it warrants further examination.


Checking Our Sums

Hartsfield doesn’t cite any source for the twenty million deaths estimate, but just from what we have, there are reasons to be suspicious of it.

Note that he says the number of Americans expected to die in a ground invasion of Japan was in the hundreds of thousands. He doesn’t give a specific number, but let’s pick one in the middle of this range and say 500,000 (which is probably on the high side).

Using that figure, and comparing it to the alleged Japanese death estimate of twenty million, that would mean there would be 40 Japanese deaths for every one American death in a ground invasion.

That figure is not plausible.

The American fighting man of 1945 was very formidable, but the idea American soldiers would kill forty Japanese people for every one of them that gave his life is not plausible.

Also note that we have the fudge phrase “as many as” in front of “20,000,000 Japanese would have lost their lives.” This suggests we are looking at an estimate on the high side of a range of estimates.

But just because somebody made an estimate that high doesn’t mean it’s a good estimate. In every age, some people make implausible estimates, and we can’t use them as a basis for decision-making.

So how reasonable was this one?

At the time, the entire population of Japan was 72,000,000, so 20,000,000 would have been 28% of that.

Would the Japanese really have suffered the loss of more than a quarter of their entire population in a ground invasion before surrendering? This strains credibility. The Japanese military may have had fanatics in leadership positions, but when a people faces costs that high, they tend to find new leaders in a hurry. It’s often a bloody process, but it happens.

Another reason to be suspicious of the twenty million figure is the absence of a plausible context. What scenario is being posited here? Presumably the Japanese government did not do an estimate, after the fact, of how many people would have died if America had not dropped the bomb. That means we’re likely comparing apples and oranges.

The logical thing to do, since we haven’t been given a source to check out, is to take to the internet and do some Googling. When we do that, a plausible source for the figure emerges:

Unfortunately antisurrender sentiment and objections from much of the Japanese military was widespread. Vice Admiral Takijiro Onishi, founder of the kamikazes, argued the Japanese "would never be defeated if we were prepared to sacrifice 20,000,000 Japanese lives in a 'special attack' effort."

If this is the source of Hartsfield’s figure then it isn’t an estimate of potential war dead in a ground invasion scenario. Vice Admiral Onishi was not saying, “If the Americans conduct a ground invasion then twenty million Japanese will be killed.”

He was saying, “If we are willing to sacrifice twenty million people in ‘special attacks’ (i.e., kamikaze/suicide attacks) then the Americans won’t win.”

That’s a very different thing.


The Problem with the Numbers Argument

While it looks like the numbers Hartsfield used in his version of the numbers argument are implausible, it is fair to say that the dropping of the atomic bombs shortened the war and thus saved net lives.

That’s the strongest argument for dropping them, which is why it’s so familiar.

But that doesn’t mean it’s a good argument.

I don’t know what religious perspective Dr. Hartsfield comes from (if any), but there is a profound human moral intuition that some things are intrinsically wrong and can never be justified, regardless of the circumstances.

This intuition is reflected in the Catechism of the Catholic Church, which states:

There are concrete acts that it is always wrong to choose, because their choice entails a disorder of the will, i.e., a moral evil. One may not do evil so that good may result from it (CCC 1756).

Targeting civilians is one of those intrinsically evil acts.

We’re not talking about accepting civilian deaths as collateral damage in a military operation. That’s a different thing. We’re talking about deliberately killing civilians.

This is regarded as a violation of the laws of war, as a barbarous act, and as a war crime.

It’s also something else.

The obvious reason to deliberately kill civilians is to instill fear and to motivate one’s enemies to comply with the course of behavior you desire.

That’s terrorism.

To deliberately kill civilians to instill fear and achieve your goals is terrorism.

And that’s what we did to Japan in 1945.

Hiroshima and Nagasaki were put on the target list because they were large cities. Regardless of what military assets they may have held, the target selection criteria specifically mandated large cities so as to deal a greater psychological blow to the Japanese.

A formerly top secret memo of the Targeting Committee from May of 1945 states that the major criteria were:

(1) they be important targets in a large urban area of more than three miles in diameter, (2) they be capable of being damaged effectively by a blast, and (3) they are unlikely to be attacked by next August.

And the actual order to drop the bomb lists the cities themselves as the targets.

Consequently, from a Catholic perspective, the bombings of Hiroshima and Nagasaki cannot be justified:

Every act of war directed to the indiscriminate destruction of whole cities or vast areas with their inhabitants is a crime against God and man, which merits firm and unequivocal condemnation. A danger of modern warfare is that it provides the opportunity to those who possess modern scientific weapons – especially atomic, biological, or chemical weapons – to commit such crimes (CCC 2314).

Of course, not everyone is Catholic, but the moral principles articulated here are based in human nature.

One can only justify the bombings if one is willing to set aside these principles and embrace the inhuman logic of deliberately killing innocent people for purposes of creating fear to achieve your ends.


The Timeline Argument

Hartsfield also mounts a second argument for the bombings being moral:

Artillery spotters like my grandfather had just about the lowest life expectancy of any troops in ground combat. He very likely would have died up in that tree, calling artillery directions into his radio. …

Fortunately, we made the right decision. Without that momentous blast shaping human history I might not be alive today. Millions of you can count the same blessing. Remember that.

One doesn’t hear this argument as often as one does the numbers argument, and there is a good reason for that.

While it may personalize the situation, it’s exceptionally weak.

For a start, it doesn’t do anything to address the fact that an intrinsically evil act cannot be justified by good consequences that flow from it.

It may be true that if Japan had not been nuked that Dr. Hartsfield’s grandfather would have died and Dr. Hartsfield would not have been born, but this does not justify the act if killing innocent people is intrinsically evil.

Consider a parallel, intrinsically evil act: rape.

There are many people who were conceived by rape, but it would be fallacious to say, “It was a good thing my mother was raped, because otherwise I wouldn’t exist. The rapist made the right decision.”


It’s a good thing that you exist, but that does not justify the rape of your mother—or any of the other innumerable acts of evil in the timeline leading up to your birth.

Unless every individual is fated to be born no matter what happens (in which case it wouldn’t matter if we dropped the bomb or not) then our timeline is exceedingly fragile.

Think about the circumstances of your conception: There were around 200,000,000 sperm competing for the chance to unite with the available ovum. If your parents had done anything different that night—ate dinner at a different time, gone out to a movie instead of watching TV, spent a few extra moments talking—then they would have had a child who was not you.

And if their parents had done anything different, they would not have been born either—and so on, back into the mists of time.

From a faith perspective, this all happens as part of God’s providence, but on the natural level, we are all the product of a huge collection of compounding butterfly effects.

That means it wasn’t just the dropping of the atomic bomb that led to your birth—it was the entire complex of all the events in human history that did.

Yet there’s no way you can look at all the events in that history—all the wars, rapes, murders, acts of barbarism and savagery—and say they were all “the right decision” because they led to your birth.

Dr. Hartsfield is right that if we had not dropped the bomb then he would not have been born—and neither would anyone else born after 1946 (to leave room for all those in utero at the time).

But then a whole different group of people would have been born.

And they would have been able to look back on 1945 and employ the same logic as Dr. Hartsfield, saying, “It’s a good thing we didn’t drop the bomb. That was the right decision, because otherwise it wouldn’t have lead to our births.”