For Woodrow Wilson, the idealism he espoused led to creation of the visionary but ill-fated League of Nations. In the case of John Kennedy, the lofty view of America's role in the world translated into the Peace Corps and the Alliance for Progress, an attempt to right the northern giant's relations with its southern neighbors.
Each of these projects, successful or not, can be seen as a presidential attempt to confront the traditional isolationism of the American people with the idea that their country must be a beacon to the world for its own good. It is in this vein that some observers are viewing President Bush's "freedom" speech.
The president's wide and idealistic optic on America's role, as laid out in his inaugural address last week, may not be the harbinger of new policies or grand new projects, experts and the president's staff say. Even Mr. Bush's father, the first President Bush, warned over the weekend against reading too much into his son's message, saying it does not portend "arrogance" or a more interventionist foreign policy.
But the president certainly had a reason for focusing his speech on the goal of ending tyranny around the world by extending freedom, observers say.
One view is that Bush was not so much speaking to the world, as some have interpreted the speech, but to the American public. This view sees Bush as essentially arguing against America's isolationist streak by making the link between global liberty and democracy and America's security.
"Again and again, he says America's future lies abroad, especially by tying security at home to freedom abroad," says Thomas Henriksen, a foreign-policy scholar at the Hoover Institution in Stanford, Calif. The president "is essentially casting off America's isolationist tendencies and explaining why we can't go back there."
Although Bush did not mention "Iraq" once, White House aides have since said the speech was in fact all about Iraq as an explainer of why the United States must remain committed there - and indeed throughout the Middle East.
With US public support for the war falling below majority levels, Mr. Henriksen says Bush is offering a reasoning why the US must stick with the Iraq project.
"If [Iraq] doesn't work, it could set off another round of inward-looking, and Bush sees that," he says. The isolationist reflex kicked in after Vietnam and even after the cold war, historians note.
One reason the president may have felt so strongly about making this case to the American people - Bush told White House aides shortly after the election that he wanted his inaugural address to focus on freedom and America's role in spreading it - is that it flows from a philosophical transformation he himself underwent.
"Bush saying we can't just rely on ourselves anymore sounds the same as Roosevelt, but it's a great change for [Bush]," Henriksen says. At the outset of his first term, Bush touted a "humble" US foreign policy and eschewed nation-building of the kind now being pursued in grand scale in Iraq. Bush discarded his old thinking as a result of what he calls the "day of fire" on Sept. 11, when foreign terrorists brought their rage to American shores.
Still, with the US preoccupied with Iraq, the "Bush doctrine" of ending tyranny should not be seen as portending new policies or radical shifts in approach to other countries.
Neoconservative standard-bearers of the muscular approach to America's global calling - some of whom, like Weekly Standard editor William Kristol, were consulted by Bush for his speech - say the "Bush doctrine" is not about creating any new programs or world institutions. They also say it's already having a profound impact. They point to increased debate across the Middle East and steps toward reform in a number of countries as evidence of a building response to US pressure.
One case in point is Iran, where Bush's speech led to a quick response. On Sunday, Tehran's Foreign Ministry spokesman Hamid Reza Asefi said recent comments by Bush and other US officials "are clear examples of cultural and religious war which will only lead to people's hatred of US policies ... and will isolate America more than before," according to wire reports.
Bush did not mention Iran in his speech but in other comments said the US had not ruled out military action if diplomacy cannot stop Iran from pursuing nuclear weapons. At the same time, Vice President Dick Cheney placed Iran atop a list of world trouble spots and warned that Israel could decide to bomb its nuclear facilities.
Calling such talk "psychological warfare," Mr. Asefi said Iran still expects Bush in his second term to work more closely with the international community "to handle the countries that are not following international demands."
Others say Bush's words should be heard more as a philosophical statement than as a call to new action. In speaking to reporters Saturday, the president's father said the inaugural speech "doesn't mean instant change in every country - that's not what he intended."
But even in that context, the speech is likely to have practical impact down the road, according to some experts with government experience.
"I'm not sure his intent is to have immediate impact on policy, because after all there is this remarkable gap between the rhetoric and policy as followed on a number of places, from Egypt and Pakistan to Russia," says Thomas Carothers, an expert on democracy promotion at the Carnegie Endowment for International Peace in Washington.
Once at the helm of the State Department, Condoleezza Rice may announce an envoy for the Israeli-Palestinian conflict or a special coordinator for Middle East reform, he says, but nothing more dramatic than that should be expected.
Still, Mr. Carothers says Bush's speech is likely to be "influential" over a long period because it will be cited by policymakers who will use it as support for what they want to get done.
A State Department official during the Reagan presidency, Carothers says he recalls the impact of "a couple of high-octane speeches on democracy" that Reagan gave in the early 1980s. "It was useful to people who really wanted to do something on democracy and human rights. They could say, 'But that is the president's policy, remember what he said?' "
For those bent on getting something done, Carothers says, "It gives you ammunition."