To visit the Franklin Delano Roosevelt Memorial in Washington is almost to come face to face with the obsessions of the 1990s—the memorial was dedicated in 1997—rather than to meet the man who served as president of the United States from 1933 to 1945. There are inscriptions about the welfare state, the environment and world peace, but one gets little inkling of the man who conjured the American superpower out of economic and wartime devastation. Likewise, Dwight Eisenhower these days is most often mentioned in the context of his warning about the dangers of a military-industrial complex. Less frequently cited: Eisenhower's secret threat to use tactical nuclear weapons to end the Korean War and his aggressive use of the clandestine services to further American interests.

Eisenhower, like Roosevelt, saw the projection and expansion of American power as synonymous with good in the world. Because all ages manipulate the past to suit their needs, these two presidents, who governed at the height of American supremacy, have had their legacies to some extent distorted of late, at a time when the elite is apologetic about American dominance and frankly doubts its prospects. In "Architects of Power," a short, elegant and incisive study, Philip Terzian, the literary editor of The Weekly Standard, sets out to write a corrective.

Putting Roosevelt and Eisenhower together is itself a deft device: For the generation of the baby boomers, who have no living memory of World War II but do have one of the Cold War, there is a tendency to romanticize Roosevelt and even Harry Truman while treating Eisenhower as a mere mortal. In truth, the Cold War was a tailpiece of World War II in Europe, and thus Eisenhower's labors flowed naturally from Roosevelt's.

The heart of Mr. Terzian's thesis is that Roosevelt saw World War II as an opportunity to forge an American empire, or its rough equivalent. Roosevelt had been an "enthusiastic supporter" of the Spanish-American War, which won strategic perches for the U.S. in the Caribbean and western Pacific, and he championed military power as assistant secretary of the Navy. As early as 1937, when America was in a quasi-isolationist mood, Roosevelt said in a Chicago speech that "we cannot have complete protection in a world of disorder in which confidence and security have broken down."

Roosevelt intuited in 1940 that the defeat of France and the isolation of Britain created an unprecedented opening for the U.S., especially if America could defeat Nazi Germany: Hitler's fall would lead to long-term German emasculation of some sort, given the rising power of the Soviet Union in the east. As for the United Nations, Roosevelt viewed it, in Mr. Terzian's words, as an "instrument of American leadership," however internationalist Roosevelt's rhetoric might have been as the U.N. was aborning in his last years.

Mr. Terzian believes that Roosevelt's "unsubtle slighting" of Churchill at the Tehran and Yalta conferences, and the president's closer attention to Stalin, have been misinterpreted: "Roosevelt made the mistake of suggesting to the British that his personal charm might be persuasive with Stalin when, of course, he believed no such thing." Roosevelt, the author maintains, "did not seek to seduce Stalin" but to make it clear to him that, "no matter the condition of Britain and Western Europe, the United States was not prepared to cede the postwar world to Russian diktat."

Eisenhower, who combined "geniality" and "cold calculation," directed U.S. policy with "unilateral discretion," Mr. Terzian says. Such quiet unilateralism emerged from Eisenhower's understanding of Western Europe's weakness. Hitler had invaded Poland before Europe had recovered from the psychological and political wounds of World War I. A second round of utter destruction had, as Mr. Terzian puts it, "only exacerbated Europe's trauma." It was a keen sense of just how enfeebled Europe was that led directly to both Roosevelt's and Eisenhower's comfort with the idea of America as a superpower. Even the quasi-pacifistic welfare states that constitute Europe today would not have been possible without the decades-long subsidy of the American security umbrella.

But while Roosevelt and Eisenhower saw American might as natural, they tried at every turn not to let their public rhetoric advertise that belief. That is a key difference between them and the recently departed Bush administration. As for the Obama administration, it has raised America's profile in Asia, stood tough behind South Korea and against Japan's initial demand to close a U.S. Marine base, and played it cool in the Persian Gulf against Iran, even as it has reached out to the Muslim world.

Republican opponents accuse Mr. Obama of yielding too much to America's enemies. But Mr. Obama may only be trying to emulate Roosevelt and Eisenhower in their skill and subtlety. If he is, he should keep in mind that rhetoric is less important than power relationships behind the scenes. Eisenhower spoke the language of peace while supporting both the 1954 coup in Guatemala and the restoration of the shah of Iran the year before, and he opposed the British-French-Israeli seizure of the Suez Canal in 1956 because it undermined American interests in the Middle East. As Iran moves closer to becoming a nuclear power, we'll see just how close Mr. Obama can come to the Roosevelt-Eisenhower standard.

Mr. Kaplan, a senior fellow at the Center for a New American Security and a correspondent for The Atlantic, is the author of "Monsoon: The Indian Ocean and the Future of American Power," to be published in October by Random House.