By Eliot A. Cohen One might think that the meaning of a word as common as strategy is clear, but it is not. The invaluable Oxford American Writer’s Thesaurus inadvertently captures the confusion: “master plan, grand design, game plan, action plan, policy, program, tactics.”But a master plan is something more specific than a grand design, a policy is what should direct strategy, and tactics exist at a level of intentional action below strategy.

The muddle becomes serious when applied to strategy’s original and most important field of human endeavor: war. The roots lie in ancient Greek, which is why stratēgos was the word for “general.”Many weighty works on strategy in war make the basic ideas clear, and yet, as one can see from the badly botched American war with Iran, strategy is acutely difficult. Here we have a war in which the United States has the world’s most advanced technology, highly skilled personnel, and well-trained and -staffed organizations.

The U.S. is operating in a theater of war that it has studied for many decades, in partnership with Israel—the most militarily advanced country in the Middle East—as well as, more quietly, most of the Gulf States, and it is receiving the tacit support of countries such as Great Britain. Its enemy is poor and corrupt, and recently lost a large chunk of its senior leadership in a series of bombings and assassinations. But the result is, in important respects, a shocking setback, as Iran continues to throttle one of the world’s most important waterways.

This happened not because America’s weapons malfunctioned, its sailors and airmen were incompetent, or the problems were novel and unanticipated. Rather, America’s battlefield reversals represent a strategic failure of an acutely embarrassing kind.

Nor is the issue simply incompetent American political leadership, although that has played its role. The history of strategy is a tale of errors, misjudgments, poor assessments, and inadequate follow-through. It was true of the ancient Greeks, when Athens held the high cards in the Peloponnesian War and lost; it was true of Germany and Japan in the two world wars they launched at times and places of their choosing; it is true of Russia today in Ukraine; it is, for that matter, true of the Iranians themselves, who suffered their own strategic failures against Iraq in the 1980s and Israel in recent years. The seven core questions of strategy may seem extremely simple, and yet they are rarely answered well.

The first is What else is going on? Strategy requires its practitioners to orient themselves to the surrounding environment, for almost never is a country simply facing off against another in isolation. When the Trump administration launched the current round of fighting with Iran, it did so having neglected its environment—indeed, in some ways, having made that environment worse. The U.S. had alienated its European allies, whose active help it needed in keeping the Strait of Hormuz open in the face of mine and surface attacks; it failed to prepare the ground with Gulf allies who would be exposed to Iranian attacks; and it underestimated the extent to which Russia and China had put themselves into a deep partnership with Iran, providing targeting intelligence, the components of military systems, and even some weapons. By fixating on the enemy at hand, the administration neglected the context that had shaped everything else.

Governments collect a great deal of intelligence about things that can be counted—tanks, ships, missiles. They do a much worse job of answering the second question, which can be derived from an unlikely classic of strategy: the 1969 movie Butch Cassidy and the Sundance Kid. Paul Newman and Robet Redford play two relatively nonviolent train robbers in the last days of the frontier. One day, as they are holding up a train, a boxcar door slides open and they are pursued by half a dozen men on horseback.

Exciting chase scenes ensue as Butch and Sundance try every trick in their extensive playbook to shake them off, but still the pursuit continues. In bafflement, Butch asks Sundance, “Who are those guys?”It is the second great strategic question, and a subtle one.

The two robbers knew how many riders were pursuing them and what weapons they carried. They could probably even tell the breed of horses they were riding. But they did not know what made this band of lawmen so much more persistent and so adept in seeing through their dodges—what motivated them, and what that would mean for Butch and Sundance.

That sort of intelligence is difficult to come by, particularly if you do not know that that is the information you need. President Trump and his key advisers likely knew little about the leaders of the Islamic Revolutionary Guard Corps, who are now their primary opponents. It is clear that they still cannot fathom how their enemy makes decisions. It is not uncommon for Western leaders to underestimate or simply fail to grasp the ideological or religious motivations of their enemies, and that seems to be part of what has happened in the conflict with Iran.

But it seems as well that the administration and its advisers misjudged Iran’s preparedness to launch a protracted, complex war in which it would be outgunned but not necessarily outsmarted.

The problem is probably reciprocal: If Iran’s leaders have taken the so-called TACO bet—“Trump Always Chickens Out”—they have been repeatedly proven wrong, as indeed have been many of Trump’s domestic critics. They may understand Trump, his motivations, his stock of resolve, and his fears as little as he understands them. Or for that matter, as little as the Israelis understood Yahya Sinwar, the leader of Hamas, even though they had had him in their prisons for 10 years, or as little as Americans understood the calculus of Japanese decision makers in the fall of 1941.

Sometimes it is possible not even to know who is in charge on the other side. During most of the Vietnam War, American leaders believed that the charismatic Ho Chi Minh or the experienced General Võ Nguyên Giáp were making the decisions. Later they suspected that it was a collective leadership. In reality, the dominant figure was the colorless first secretary of the Communist Party, Lê Duẩn. In the current war, Trump has frequently expressed his frustration at not knowing who is in charge on the other side.

What are we trying to do? is the third and most obvious strategic question, perhaps the easiest to pose and the most deceptive. When critics have gone after the Trump administration over the Iran war, they have usually focused on the supposed unclarity of its goals. They have something of a point, but to a more limited degree than one might think. In truth, the setting of goals, although vital, is a murky and shifting enterprise.

Carl von Clausewitz, who in his lifetime witnessed numerous strategic defeats as well as the ultimate victory of the allied coalition over Napoleonic France, taught that war is a continuation of policy by other means. It may be the most important teaching to take away from his classic, On War, and is certainly the most memorable. But if the ultimate objectives in war are political, then they also have political characteristics—that is, they may be vague, inconsistent, and above all changeable.

George H. W. Bush famously outlined four objectives for American forces in advance of the 1990–91 Gulf War, in an oft-cited example of strategic clarity. A closer look, however, shows that they were anything but clear. The first objective was ensuring the safety of American citizens in the Gulf—but before the bombs fell, that had already been achieved, because the Iraqi dictator Saddam Hussein had released his American and European hostages. American citizens—the soldiers, sailors, airmen, and Marines going into Iraq—were the ones endangered by the war.

Expelling Iraq from Kuwait was straightforward enough, but restoring the “legitimate government of Kuwait”—a monarchy backed by a citizenry that included scarcely a quarter of the country’s inhabitants—was not. And as the events of the past 35 years have proven, the fourth objective, ensuring the stability of the Persian Gulf, was a pipe dream.

Moreover, some of the objectives the United States pursued either were unstated (stripping Saddam of his nuclear program and setting up the conditions for his overthrow) or evolved only in reaction to events on the ground (protecting the Kurdish population in the north and, to some degree, the Shia in the south).

This kind of shift in objectives occurs in all wars. Britain entered World War II nominally to save Poland from Germany. It ended up prohibiting Polish troops from marching in the victory parade in London. The United States invaded Afghanistan to destroy al-Qaeda; it ended up attempting to create an Afghan democratic republic.

Considered in this light, the Trump administration’s objective-setting in the Iran war, though messy, is not entirely implausible. Clearly, one objective has been to destroy, or at the minimum badly damage, Iran’s nuclear enterprise; another to limit its ability to threaten its neighbors with missile and drone attacks by dismantling some of its key military industries. A third, and the most questionable, seems to have been to overthrow and replace the regime. That last goal is evidently beyond the current reach of the U.S. military, although the other two have been achieved in some measure.

As the war has wound on, the administration has reached for other goals, including the bizarre one of keeping “oil and gas cheap for Americans all over the country,” which Vice President Vance has declared now has primacy over avoiding a nuclear Iran.

One problem with the Trump administration’s objective-setting is the president’s foolish insistence that he has achieved more than he has: His repeated use of the word obliteration actually obscures some real, if far from absolute, successes in pursuit of his first two objectives. As for the third, it was always bound to be a reach but was not beyond the realm of possibility. The administration’s real failures have come in setting what were essentially defensive objectives in addition to the offensive ones, above all securing the Strait of Hormuz.

For the rest, like many administrations before, it has promised much more than war can ever deliver—think of the hubris of the “war to end all wars,” or the objective of ending tyranny. In democratic societies, the temptation to justify the hazards and sacrifices of war with overblown rhetoric and absurd aspirations usually overcomes the good judgment of political and military leaders alike.

What are our means? is the fourth question. At a strictly quantitative level it is usually easily answered by counting tanks, missiles, or ships. But those are often the least important variables in the equation. The real variables are whether organizations can do what we want them to do; whether the technical means we have at our disposal are adequate to the task; and whether, if new challenges arise, we have the resources to meet them.

The United States entered the current war with limited stockpiles of its most advanced weapons, limited mine-clearing capabilities, and no frigates whatsoever to escort convoys. It had very little in the way of hardened bunkers for its aircraft in the Persian Gulf, and so suffered some shocking losses on the ground to accurate Iranian missiles (possibly guided by Russian intelligence). And the entire campaign has been predicated on expectations about what bombing could do that were at best highly improbable and at worst totally unrealistic.

The administration clearly overestimated what the U.S. military could do, but one has to wonder whether the armed forces also misjudged their own capabilities. Decades of underinvestment in both passive defenses (for example, concrete shelters, underground command posts) and active ones (for example, surface-to-air missile batteries), not any particular decision of the Trump administration, have exposed the U.S. Air Force to high losses. A similar decades-long lack of commitment to the counter-mine-warfare and the escort-of-convoy missions has made the Strait of Hormuz operation so difficult.

“Know the enemy and know yourself and in a hundred battles you will not be defeated,” goes the saying of the Chinese general Sun Tzu. But military organizations and their leaders frequently fail to understand themselves, and in particular their own weaknesses. America’s lack of preparedness to conduct classical counterinsurgency warfare in Iraq and Afghanistan cost it dearly in blood, money, and time. Most militaries fail to conduct a sober reckoning with their own deficiencies by examining their lack of resources, organizational preparation, or aptitude.

The fifth and sixth questions are What is our priority? and In what sequence should we act? For a country as wealthy and powerful as the United States, these are particularly uncomfortable questions. American leaders often act as though their resources are infinite and few really difficult strategic choices need to be made. That flexibility is one of the blessings (and occasionally the curse) of an astoundingly wealthy and populous country.

Economists like the word trade-off—to get this, you have to give up that. The military uses instead phrases such as economy of force or acceptable risk that mask the blunter truth that some things are more important than others. In the current Iran war, it has become clear that getting control of the Strait of Hormuz has never been the top priority—had it been so, the U.S. would have conducted a variety of operations, probably including seizing some of the smaller islands near the strait.

Setting priorities can be acutely difficult in war. The best decision Franklin D. Roosevelt made during the Second World War was one of priority. Military and political leaders alike had believed in 1941 that Germany would be a more important enemy than Japan and needed to be tackled first. But the war began for the United States with the Pearl Harbor attack of December 7, 1941. Over the next six months, Roosevelt agreed to the British proposal to invade French North Africa in November 1942. General George C. Marshall, the chief of staff of the U.S. Army, and Admiral Ernest J. King, the chief of naval operations, thought it a strategic error and opposed it, favoring instead an invasion of France in 1943.

Roosevelt’s calculation was chiefly political: To sustain domestic support for the “Germany first” policy, American forces had to be in action somewhere in the European theater of operations within a year of Pearl Harbor. He got his priorities right, and Marshall and King, who did not think politically, were wrong. (As it happened, a 1943 invasion would probably have been an operational debacle as well for the untried U.S. Army, but that was a separate matter.)

If Roosevelt got priority right, however, he got sequencing wrong. Like most politicians, he did not want to feel trapped by prior decisions—what political scientists call “path dependence.”He believed that he could have the North Africa invasion and still invade France in 1943, and he was wrong. The defeat of German armies in North Africa took longer than expected, and was not completed until March 1943. Sicily loomed as an easy target, and besides, shifting large forces to Britain, particularly before the U-boat menace in the Atlantic was defeated, would take time, so in July the Allies attacked the island and took it.

That triggered the fall of the Italian dictator Benito Mussolini; the logical next Allied move was therefore a landing in Italy. That occurred in September 1943, in the immediate aftermath of Italy’s defection from the Axis. And that, in turn, led to a swift German occupation of Italy and an ensuing front in Europe that no one had anticipated.

Sequencing, then, was only partially under Roosevelt’s control, or anyone else’s for that matter. One thing led to another, and as is so often the case in war, the contenders looked as though they were playing chess one move at a time, seizing an opportunity without fully anticipating the consequences of doing so.

The final question is in many ways the most difficult: What is our theory of victory? Or, put more simply, Why do we think this will work?

In the case of the Iran war the theory of victory seems to be: We will inflict so much economic pain on the regime that it will give in, either because it will hate to see the Iranian economy ruined or because its people will rise up and overthrow it. But Iran has been suffering self-imposed economic misery for decades, and its leaders, with their own corrupt networks, can live in splendor while others suffer. And as for an uprising, the time to support that would have been when Iranians took to the streets in December and January 2026, before 30,000 were massacred by the Islamic Republic’s repressive apparatus.

If there is any theory of victory left for the United States, it is that more reasonable Iranian leaders will replace the extremists—but it would appear at the moment that the hardest of the hard-liners are the ones with the guns.

Articulating a theory of victory is no different from constructing a plausible story—the different characters find themselves in a situation, they do this and that, and there is an outcome. In practice, though, such theories are rarely offered in governmental deliberations—and here I speak from personal experience. I saw that play out while sitting in the Situation Room as senior officials discussed sending more soldiers, or diplomats, or aid money to Afghanistan, without anyone quite broaching the question of how the moves under consideration were supposed to lead to success.

Such failures are entirely common, as the perusal of archival records confirms. Strategy is chiefly about execution—the exceedingly complicated and difficult task of moving forces from one place to another, guiding them through combat, and responding to unforeseen circumstances. There are ancillary activities—diplomatic initiatives, the public presentation of the reasons for war or expositions of why it is going the way it is, the gathering and deployment of financial and industrial resources. All of this requires serious, detailed, and extremely consequential work. To begin telling a story, or even to ask for one, in such a circumstance can seem frivolous at best, and at worst downright subversive of the efforts officials are investing and the sacrifices soldiers are making.

Why is it all so hard? One reason lies in the sheer uncertainty of all wars, in which personalities, contingent events, accidents, bloodlust, shifting political calculations, and sheer good or bad luck play their part. But no less important are the weaknesses of the decision makers themselves.

For one, they are often, if experienced, old and suffering the afflictions of age, or if young, inexperienced and either cocky or timid. Historians will parse the records of the Trump administration or, like the cardiologist of the late Vice President Dick Cheney, wonder what it meant that the president was clearly in poor physical and possibly mental health. He would hardly be alone.

Prime Minister Anthony Eden launched the Suez operation of 1956 against Egypt’s Gamal Abdel Nasser. At the time, he had been hospitalized with a fever of up to 106 degrees following a set of badly botched gallbladder operations. He had been taking amphetamines and sleeping pills. In a fascinating study of Eden, David Owens, himself a former foreign secretary and a physician, concluded that Eden’s physical health played a large role in the poor decision making that helped produce a major debacle.

Roosevelt was on the edge of death in the last year of World War II; Winston Churchill had a heart attack; and Joseph Stalin, in addition to suffering from hypertension, had become increasingly paranoid. John F. Kennedy took a horrifying cocktail of drugs for his bad back and suffered from Addison’s disease. Woodrow Wilson had an incapacitating stroke that left the U.S. government largely in the hands of his protective wife. These are not isolated cases.

Even healthy younger leaders may find themselves suffering from acute sleep deprivation and other disorders. A flattering portrayal of President Biden’s national security adviser noted that, during the American withdrawal from Afghanistan in 2021, Jake Sullivan was getting two hours of sleep a night for days on end. As those who have studied medical residents know, going that short of sleep practically guarantees poor decisions.

The psychologist Daniel Kahneman and his colleague Amos Tversky have examined many heuristic shortcuts that distort rational decision making. Almost all of them apply in strategic decision making as well. Take anchoring, our tendency to judge an event, problem, or cost based on some existing piece of information. The trivial case is the extremely expensive bottle of wine put on a restaurant menu with the idea of making the second- or third-most-expensive bottle look reasonably priced.

Strategic anchoring occurs frequently. In the run-up to the German invasion of the Soviet Union in June 1941, not only Hitler but also his generals concluded that Russia was a fragile giant. They anchored their perceptions on the 1939–40 winter war between the U.S.S.R. and Finland, when 200,000 Soviet troops were killed, wounded, or captured by Finnish militiamen. They paid no attention to the way in which the Soviets had learned swiftly from their failures in that war, and did not account for all of the advantages that Russians would derive from fighting on their own ground.

In a similar vein, both the Russian military and Western observers anchored their perception of Ukrainian fighting power in the 2014 and 2015 rounds of conflict in the Donbas as well as the Russian seizure of Crimea. They had discounted, or simply ignored, the improvements in Ukrainian training and equipment since then, or, in parallel with the 1941 case, the differences that would emerge when Ukrainians were fighting to protect their villages and cities from an army that would commit rape and murder with abandon.

Strategic decision making is rarely a matter of individual choices; more often it is the result of some kind of deliberation. This is true even in the most extreme totalitarian countries. Stalin called the shots, but Marshal Georgy Zhukhov could get a hearing. This leads to another obstacle to sound strategic judgment: collective pathologies. The phenomenon described by Irving Janis as groupthink applies particularly forcefully to strategic decision making: illusions of invulnerability, collective discounting of warnings, unquestioned belief in one’s own inherent morality, stereotyped views of adversaries, self-censorship, and the exclusion of dissidents, or their reduction to marginal status. Lyndon Johnson heard out George Ball, the in-house dissenter on Vietnam, and then moved swiftly on.

These and many other pathologies have beset not only the Trump administration in Iran, but most countries at war. They can be mitigated but not resolved. Formal procedures are less helpful than qualities of character. Of these the most important are empathy, to understand both the enemy and one’s own side; curiosity, because every war is new and distinctive; humility, to accept that one has made mistakes; and above all moral courage, to face facts for what they are and to make decisions accordingly.

The president is singularly deficient in all of these aspects. He finds it difficult to imagine the world as seen by others; he seems to be incurious about the important details of military operations; he is far from humble; and if he is averse to anything, it is admitting that he might be wrong. These traits do not seem, moreover, to be confined to him but are shared by many in his administration.

The strategic virtues, to be clear, are rarely found. But they do exist. Churchill, whose courage was justly famous, was a great war leader. He benefited as much, however, from his empathy as from his courage. His great advantage over Hitler, as the historian John Lukacs has shrewdly noted, is that he could imagine what it was like to be Hitler, but Hitler could never imagine what it was like to be Churchill. One cannot study Abraham Lincoln’s conduct of the Civil War without being struck by his curiosity and humility—neither of which interfered with his resolve and decisiveness.

Nor is it the acknowledged great figures of history alone who show these qualities: When President George W. Bush made the call in December 2006 to surge forces to Iraq despite the apprehensions of his military and political subordinates, he exhibited considerable moral courage. Israeli Prime Minister Levi Eshkol made a number of decisions in the run-up to the Six-Day War that bought Israel at least a modicum of the support and understanding that it would need from abroad, and which, in very different circumstances, Prime Minister Benjamin Netanyahu has so profligately squandered.

Some view strategy as so difficult that it is not even worth attempting. These are not only counsels of despair but of nihilism. Some decision makers have shown excellent strategic judgment and used war to achieve their political objectives. The most notable might be Anwar Sadat, the long-underestimated Egyptian president who launched the 1973 Yom Kippur War and used a spectacular early success that could have easily ended in catastrophe to secure the peace he wanted.

War is a hideous thing. There are even more hideous things, however, as anyone who has visited the mass graves of Sarajevo or the slaughter field of Bucha in Ukraine will know. A war with Iran now may well be far less terrible than a war launched by an Iran with nuclear weapons later. Moreover, sometimes war is unavoidable: True pacifists are few, and no nation committed to pacifism has survived the predations of a hostile neighbor that is not.

The chances are good that anyone reading this article lives in a country that is currently at war, or has been at war, or is closely affected by war. It is a near certainty that they live in a country whose borders have been shaped by war, and quite probably one whose form of government has resulted from war. All of us therefore have, or should have, a keen interest in strategy.

Unfortunately, however, its practice will not get any easier in the future. War is spreading to new domains, and employing new and terrible conventional weapons, many capable of acting on the basis of decisions that machines will make in fractions of a second. Nuclear weapons are spreading, and we now face the potential of devastating biological weapons manufactured with the aid of artificial intelligence. The previous experiences and professional knowledge of generals and admirals becomes ever more swiftly obsolete; the hazards of untried political leaders wading through such uncertainty, immensely greater. More countries have the capacity to do terrible things, and are seemingly willing to do so.

None of that is an excuse for neglecting the subject that Aristotle thought essential for a citizen. In his Rhetoric, he talks at length about the subjects an orator must master, including “the military strength of his country, both actual and potential, and also the nature of that strength; and further, what wars his country has waged, and how it has waged them. He must know these facts not only about his own country, but also about neighboring countries; and also about countries with which war is likely, in order that peace may be maintained.”Strategy is one of the oldest of subjects.

It is powerfully shaped by current events and technologies but best learned through a deep encounter with the history of war. It can be studied but rarely mastered, and it is the domain of both calculation and inevitable error. Of one thing we can be certain: As we look at a world in which violence is not the last resort for many countries and organizations hostile to our values and interests, and may very well be the first, strategy will be needed more than ever.