When the Lesser Evil Is Still Evil

Why It Matters

The curriculum has spent considerable time on the dangers of moral cynicism: the Athenian argument at Melos, the Eichmann type, the person who goes along with injustice through thoughtlessness or self-interest. This lesson addresses the opposite danger — the danger of moral perfectionism: the conviction that genuine moral seriousness requires finding an option with no evil attached to it, and that the absence of such an option is a reason for paralysis or for an indefinite search for cleaner hands.

The problem of the lesser evil is not a marginal case in political history. It is one of the central recurring problems of political leadership. Every major war produces it. Every public health emergency produces it. Every serious political crisis in which the available options are all genuinely bad produces it. The leaders who faced these choices — Truman at Hiroshima, Churchill at Dresden, Lincoln suspending habeas corpus — made decisions that caused real, documentable suffering to innocent people, and that were, by some accounts, necessary to prevent even greater suffering. Whether those accounts are correct is genuinely contested. What is not contested is that the choices were made, that they had real moral costs, and that the leaders who made them were not simply wrong to make them.

Understanding how to think about genuine tragic choices is preparation for a world in which you will, at some scale, face them. Not the world-historical scale of Truman or Lincoln — probably not. But the person who has never thought about the structure of tragic choice will face their much smaller version of it with no framework at all, and will either choose in bad faith — pretending the moral cost doesn't exist — or be paralyzed by the impossibility of a clean outcome.

A Story

Three Decisions, Three Weights

In August 1945, Harry Truman ordered the atomic bombing of Hiroshima and Nagasaki. Between 129,000 and 226,000 people died — the range of estimates reflects the difficulty of counting the dead when the city itself has been vaporized. The majority of the dead were civilians: factory workers, schoolchildren, housewives, doctors. Some of them were Korean forced laborers. Some were American prisoners of war. None of them voted for the war. None of them made the decisions that started it.

The argument for the decision — advanced by Truman, by his advisors, and by most mainstream American military historians — is this: the alternative to the atomic bombs was an invasion of the Japanese home islands. Military planners estimated between 250,000 and one million American casualties, with Japanese casualties likely in the millions. Japan's military leadership had made clear through its actions at Iwo Jima and Okinawa — where soldiers and civilians fought to the last rather than surrender — that it intended to defend the home islands with the same ferocity. The bombs ended the war in days. The invasion would have taken months or years and might have killed more people than the bombs did.

The argument against — advanced by historians like Gar Alperovitz and Tsuyoshi Hasegawa — is that Japan was already on the verge of surrender when the bombs were dropped, that the Soviet entry into the war on August 8th (between the two bombings) was a more decisive shock to Japanese decision-making than the bombs themselves, and that the primary motivation for using the bombs was as much about demonstrating American power to the Soviet Union as about ending the war. On this reading, the bombing of Hiroshima and Nagasaki was not the lesser evil but an unnecessary evil, used while better options existed.

The historical debate has not been resolved. It probably cannot be resolved with certainty, because it involves counterfactual questions about what would have happened had the bombs not been used. What can be said with certainty is this: Truman made a choice. It killed between 129,000 and 226,000 people. He believed it would save more lives than it cost. He may have been right. He may have been wrong. And he seems to have genuinely understood the weight of what he had done: 'I have told the Secretary of War, Mr. Stimson, to use it so that military objectives and soldiers and sailors are the target and not women and children. Even if the Japs are savages, ruthless, merciless and fanatic, we as the leader of the world for the common welfare cannot drop this terrible bomb on the old capital or the new. He and I are in accord. The target will be a purely military one.' He wrote this before Hiroshima. Hiroshima was not a purely military target. He used the bomb, and he knew the moment it landed that he had been wrong about that.

Six months earlier, in February 1945, Bomber Command under Arthur Harris had conducted the firebombing of Dresden, a German city of about 640,000 people that had largely escaped the war until then. The bombing killed between 22,700 and 25,000 people — a much smaller toll than Hiroshima, but the debate it produced was structurally similar. Dresden had some military value: it was a transportation hub, it had some industrial production, German troops passed through it. But it was also one of the most beautiful cities in Europe, full of civilians, with no significant air defenses. The bombing was designed partly to demonstrate Allied air power, partly to support Soviet operations, partly because the logic of total war had made civilian morale a legitimate military target.

Churchill, who had authorized the bombing strategy, wrote a private memo afterward questioning whether area bombing had been 'too savage and too universal.' Then, under pressure from his own military advisors who felt he was criticizing them unfairly, he rewrote the memo to remove the self-criticism. He distanced himself from the policy he had authorized. The moral discomfort was real; his response to it was not entirely honest.

Abraham Lincoln, in 1861, suspended the writ of habeas corpus without congressional authorization — detaining people indefinitely without charge or trial. He later expanded the suspension dramatically, authorizing military tribunals for civilians, suppressing critical newspapers, and imprisoning state legislators who might vote for secession. He did this to prevent Maryland from leaving the Union and surrounding Washington. Chief Justice Taney ruled that Lincoln had exceeded his constitutional authority. Lincoln ignored the ruling. His argument was simple: if the Union collapsed, the Constitution would be meaningless; the temporary violation of constitutional rights was necessary to preserve the document that guaranteed those rights. This is a coherent argument. It is also an argument that every authoritarian in history has made about their own emergency powers. The difference between Lincoln and a tyrant is not in the logic — the logic is identical — but in the fact that Lincoln actually stopped when the emergency ended, returned power to constitutional processes, and submitted to election rather than using his emergency powers to remain in office.

What do these three cases share? Each involves a leader who chose to cause real suffering to real people, in the belief that the alternative would cause more suffering to more people. In each case, the belief was at least plausible, possibly correct, and not verifiable with certainty. In each case, the leader chose. In each case, the choice had moral costs that did not disappear because the alternative might have been worse. The lesser evil is still evil. And the moral seriousness of the leader — which separates them from the purely cynical operator — is visible in whether they understood and carried that weight, or whether they used the logic of necessity to stop thinking about what they had done.

Vocabulary

Tragic choice

A choice between options all of which involve real moral costs — where there is no clean or right answer, only worse and less-bad outcomes. Distinguished from ordinary hard choices (where one option is genuinely better) by the genuine moral weight of the evil embedded in the best available option.

Moral residue

The philosopher Bernard Williams' concept: even when choosing the lesser evil is the right decision, the evil in what you chose leaves a 'moral residue' — a weight of regret, obligation, or guilt that does not simply dissolve because the decision was justified. The person who feels nothing after choosing the lesser evil has not fully grasped what they have done.

The lesser evil principle

The consequentialist argument that when all available options involve moral costs, the right choice is the one with the least total moral cost. The principle is often invoked to justify harmful actions; its legitimate application requires genuine evidence that the alternative was worse, not merely assertion.

Dirty hands

The political philosopher Michael Walzer's concept: political leaders who make morally serious decisions — including, sometimes, terrible ones — inevitably get 'dirty hands.' The moral leader acknowledges the dirt rather than pretending their hands are clean. The immoral leader either refuses to act (keeping their hands clean at others' expense) or acts without acknowledging the cost.

Emergency powers and constitutional order

The political and legal problem of what happens when constitutional limits on government power are suspended in emergencies. Lincoln's suspension of habeas corpus illustrates both the genuine need for emergency powers and the difficulty of limiting them: the same logic that justifies one suspension can justify any suspension, and the test of whether a leader will restore constitutional order is only available in retrospect.

Guided Teaching

Begin with the philosophical structure before the historical cases. Ask your student to think of a situation — real or hypothetical — where every available option involves real costs to real people, where there is no clean path. Ask: 'What do you do in a situation where every option is bad? Does the badness of all the options mean that any choice you make is equally defensible — or does it mean that you must choose the least-bad option and carry the weight of having done so?' Establish the concept of tragic choice before loading it with historical controversy, so the framework is clear when the cases arrive.

The Truman/Hiroshima case should be engaged with historical seriousness. Do not let it become a simple exercise in 'was it right or wrong.' Ask: 'What evidence would you need to determine whether dropping the atomic bombs was the lesser evil? What do you actually need to know?' The answer involves: the probability of invasion and its estimated cost, whether Japan was truly on the verge of surrender, and the moral status of using a weapon that cannot discriminate between combatants and civilians. Then ask: 'Even if Truman was right about the numbers — even if the bombs did save more lives than they cost — does that make what happened at Hiroshima not evil? Or does it make it evil that was, on balance, the right decision?' This is the concept of moral residue in practice.

Churchill's self-censorship is the moral psychology lesson. Churchill wrote a memo questioning whether area bombing had been too savage. Then he deleted the self-criticism. Ask: 'Why did he do that? What does deleting the self-criticism tell you about his moral relationship to what he had authorized?' Then ask: 'What is the difference between Churchill revising his memo and Lincoln, who acknowledged the constitutional violations he had committed while insisting they were necessary? Is there a meaningful moral difference between the two responses to dirty hands?' The contrast is between a leader who carries the weight and a leader who tries to put it down.

Lincoln is the most philosophically interesting case. Ask: 'Lincoln used the logic of emergency to justify constitutional violations. That is the same logic every authoritarian uses. What is the difference between Lincoln using it and Stalin using it?' This is a genuinely hard question. The answer involves what Lincoln did after the emergency: he submitted to election, returned power to constitutional processes, and did not use his emergency powers to remain in office. Ask: 'Does that vindicate his use of emergency powers? Or does it simply mean he happened to be a decent person, and the logic he used could equally well have been used by someone who wasn't?'

End with the personal application. Your student will not face the decisions Truman, Churchill, or Lincoln faced. But ask: 'What is the version of this problem that you will face? In your career, in your community, in your family — what kinds of choices will require you to cause some harm in order to prevent greater harm? And what does moral seriousness require of you in those choices — beyond simply making the calculation correctly?' The answer involves the concept of moral residue: the acknowledgment of what you have done, the grief for what it cost, and the refusal to let the justification become a reason for not feeling the weight. Moral seriousness is not just getting the calculus right. It is carrying the result.

For Discussion

1. 1.Was Truman's decision to drop atomic bombs on Hiroshima and Nagasaki the lesser evil, or an unnecessary evil? What evidence is most relevant to that determination, and what do you actually know about it?
2. 2.Bernard Williams argues that even justified choices of the lesser evil leave a 'moral residue' — a weight of regret that doesn't dissolve because the decision was correct. Do you think this is true? What function does this moral residue serve — what would be lost if someone could make the right tragic choice and feel nothing about it?
3. 3.Lincoln violated the Constitution to save the constitutional order. Churchill bombed civilians to end a war that was killing civilians. Truman killed hundreds of thousands to prevent a military campaign that might have killed millions. In each case, the logic is the same: greater harm prevented lesser harm justified. Is there any way to distinguish legitimate from illegitimate uses of this logic, beyond simply hoping that the leader is honest about the evidence?
4. 4.Michael Walzer argues that political leaders inevitably get 'dirty hands' — that moral seriousness in politics requires being willing to do harmful things and acknowledging that you have done them. Do you agree? Is there an alternative — a way of exercising political power that avoids this problem?
5. 5.What is the personal version of the lesser evil problem — the scale at which you will face it in your own life? How does thinking about Truman or Lincoln help you prepare for that?

Practice

The Decision Memo

1. 1.Choose one of the three cases from this lesson — Truman/Hiroshima, Churchill/Dresden, or Lincoln/habeas corpus — and write a decision memo in the voice of the leader, as if you were writing it at the moment of decision.
2. 2.The memo should include:
3. 3.1. A clear statement of the choice and the options available.
4. 4.2. The evidence for and against each option, as it was available at the time (not in retrospect).
5. 5.3. The moral cost of the option you are choosing, stated explicitly and honestly.
6. 6.4. Why you believe this cost is less than the cost of the alternatives.
7. 7.5. What you believe you owe to the people who will pay the cost of your decision.
8. 8.The memo should be 400–600 words. It should not pretend the decision is easy or that the chosen option is good. It should demonstrate that you have understood the moral weight of what you are choosing.
9. 9.After completing the memo, write a one-paragraph reflection: reading it back, do you believe the decision was right? And do you feel the weight of it — the moral residue Williams describes? If not, what does that suggest about how you wrote the memo?

Memory Questions

1. 1.What is a tragic choice, and how does it differ from an ordinary hard choice?
2. 2.What is Bernard Williams' concept of 'moral residue,' and what function does it serve?
3. 3.What is Michael Walzer's concept of 'dirty hands,' and how does it apply to the three historical cases in this lesson?
4. 4.What is the lesser evil principle, and what evidence is required to apply it honestly?
5. 5.How did Lincoln justify his suspension of habeas corpus, and what is the philosophical problem with that justification?