Taft + Wilson + Kennedy + Nixon = Bush 43. The political calculus is often unpredictable.

George W. Bush inspires unusually passionate support and provokes unusually passionate opposition. The gap between the two – think of it as the presidential passion gap – suggests that future historians will fight with unusual passion about his legacy and the meaning of Mr. Bush’s presidency.

But as his presidency progresses – as he does more and as his earlier actions recede from current events into history – it is becoming increasingly clear that his decisions and initiatives are being drawn from an increasingly broad palette of precedents and presidents. He is more than an updated version of his father, or the product of the natural maturation of the ideas of Ronald Reagan – notions that many analysts, including yours truly, have argued.

Now I am not so sure that the simpler explanation works. Now, especially in foreign policy, I think he is an enigmatic admixture of four presidents, two Democrats and two Republicans, two peacetime presidents and two wartime chief executives, two from early in the 20th century and two from the postwar midsection of the 20th century.

His supporters and detractors alike argue that the president is 100 percent George W. Bush. But I am coming to the conclusion that he is one part William Howard Taft, one part Woodrow Wilson, one part John F. Kennedy and one part Richard M. Nixon. Here are the raw materials of the diplomatic Bush:

Dollar diplomacy. This was Taft’s approach to foreign policy, but the memorable phrase from the initiative, the substitution of dollars for bullets in diplomacy, is somewhat misleading and narrow. What Taft promoted was an Americanized version of the notion (borrowed from Palmerston, the 19th-century British leader) that American foreign policy should be motivated less by alliances and more by interests.

The heart of this philosophy is the congruence of American diplomatic and economic goals. Warning: This argument does not lead to the conclusion that the Iraq war is, as the president’s critics argue, a war for oil. But it leaves open the likelihood that American interest in Iraq would be substantially less ardent if there were not a drop of oil in the country or in the region where Iraq plays so important a role.

Self-determination. This principle, so shiny in its idealism during the World War I years, was at the heart of Wilson’s Fourteen Points, and the president, the son of a Presbyterian minister, converted it into a secular religion and preached it from every rooftop. Wilson’s great conviction was that democratic procedures were so ennobling, so empowering, so persuasive, that they could end centuries of international contention and overcome generations of culture and customs. That is precisely what Mr. Bush and some of his neoconservative allies believe about the transformative potential of democracy in Iraq. And that is why the president’s skeptics, especially on the right, deride his foreign policy as “Wilsonian” – a word that once meant starry but stubborn idealism, but recently has become a harsh term of opprobrium.

Bear any burden. President Kennedy’s inaugural address is remembered for its soaring, poetic language and for its invitation for Americans to ask what they could do for their country. But embedded in the fourth paragraph of that speech – in a particularly lyrical passage – is another invocation: “Let every nation know, whether it wishes us well or ill, that we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, to assure the survival and success of liberty.” That, in a Ted Sorensen phrase, is the post-weapons-of-mass-destruction Bush doctrine in Iraq. Kennedy simply said it better.

Vietnamization. President Nixon did not invent the Vietnam War, he merely inherited it. It is possible to argue that President Bush didn’t invent a crisis in Iraq, he merely inherited one. (How quickly we have forgotten those Clinton-era confrontations over weapons inspectors in Saddam Hussein’s fortress nation.) Nixon’s approach to the distress of Vietnam was to pass on the burden of the fight, from American GIs to Vietnamese soldiers.

The Vietnamization process followed Secretary of Defense Melvin Laird’s visit to Vietnam six months earlier, a mission that led to an increase in the training and equipping of South Vietnamese forces. The president gave his big Vietnamization speech to the American people almost exactly a year to the day after his election to the White House.

An aside: His remarks of Nov. 3, 1969, represent the apotheosis of the Nixon genre; he constantly says there are easier ways out of the Vietnam mess (but that he isn’t looking for the easy way) and that there are “popular and easy” policies he could pursue (but that he was too big a person, too big a strategist, “than to think only of the years of my administration and of the next election”). Just scanning this speech a third of a century later is enough to remind a reader that irritating presidential rhetorical tics were not invented in the Bush years.

But the important element of Nixon’s 1969 speech – and of his policy – is that it poses the question that both the administration and its Democratic foes are wrestling with in 2006: “The question facing us today is: Now that we are in the war, what is the best way to end it?”

The Nixon response is much like the Bush response: Pass on the responsibility for the conflict to the people who have the biggest stake in its outcome – for Nixon, the Vietnamese; for Mr. Bush, the Iraqis. Both presidents argued in favor of substituting native combatants for foreign ones. Here is Nixon: “We have adopted a plan … for the complete withdrawal of all U.S. combat ground troops, and their replacement by South Vietnamese forces on an orderly scheduled timetable. This withdrawal will be made from strength and not from weakness.”

Mr. Bush, unlike his predecessor, is not a compulsive student of the men who inhabited the White House in times far different from his own. But all Americans are hardwired with historical precedents and with the folklore of the presidents. There is nothing new under the sun, perhaps especially for a presidential son.