The most important line in President Bush’s inaugural address yesterday was this: “It is the policy of the United States to seek and support the growth of democratic movements and institutions in every nation and culture, with the ultimate goal of ending tyranny in our world.” By spelling out his bold vision of America’s role in the world as formal American policy, Mr. Bush has defined America’s purposes for a generation or more.

The president’s critics, however, have already begun to levy such well-worn epithets as “hubris” and “overreaching” in respect of the president’s policy. On CNN, reporter Judy Woodruff expressed the sense of many pundits when she described the address as an “aggressive, even militant statement by the president.” A presidential historian, Barbara Kellerman, called the president’s speech “extraordinarily ambitious.”

Maybe. But by no means, from the standpoint of history, unprecedented. In his inaugural address in 1961, President Kennedy called upon America to “explore the stars, conquer the deserts, eradicate disease, tap the ocean depths, and encourage the arts and commerce.” Kennedy aimed to create “a new endeavor, not a new balance of power, but a new world of law, where the strong are just and the weak secure, and the peace preserved” – an effort that required “a struggle against the common enemies of man: tyranny, poverty, disease, and war itself.”

President Reagan set no lesser goals. “We are not just discussing limits on a further increase of nuclear weapons,” Reagan said in his second inaugural address. “We seek the total elimination one day of nuclear weapons from the face of the Earth.”

Like Reagan, whose goal remains unmet, Mr. Bush will not likely see the end of tyranny in his lifetime. But there is no doubting the power of his vision. Just as Reagan’s “Evil Empire” speech gave comfort to the prisoners of the gulag, Mr. Bush’s address spoke directly to embattled advocates of liberty worldwide. “The United States will not ignore your oppression, or excuse your oppressors. When you stand for your liberty, we will stand with you,” the president said. “Democratic reformers facing repression, prison, or exile can know: America sees you for who you are: the future leaders of your free country.”

As the president spoke, we were struck by the degree to which he knew what he was doing. He is, after all, a president who, not long before he crafted his speech, sat with Natan Sharansky, who has spoken often and eloquently of how he, and his fellow inmates of the gulag archipelago, drew courage and hope from Reagan’s words. Surely Mr. Bush intended to kindle the hopes of those trapped in the dungeons of Tehran, Pyongyang, Riyadh, and Beijing.

Mr. Bush echoed sentiments of such predecessors as President Eisenhower, who, in his second inaugural, declared: “Our world is where our full destiny lies – with men, of all people, and all nations, who are or would be free. And for them – and so for us – this is no time of ease or of rest.”

Mr. Bush said yesterday, “America’s vital interests and our deepest beliefs are now one.” One hears the echo of Franklin Delano Roosevelt, who said at his second inaugural, “We are beginning to wipe out the line that divides the practical from the ideal, and in so doing we are fashioning an instrument of unimagined power for the establishment of a morally better world.”

At his third inaugural, FDR saw freedom on the march: “There are men who believe that democracy, as a form of government and a frame of life, is limited or measured by a kind of mystical and artificial fate that, for some unexplained reason, tyranny and slavery have become the surging wave of the future – and that freedom is an ebbing tide. But we Americans know that this is not true.”

Mr. Bush’s ambitions are those of America’s great presidents, but, far from exhibiting the blind self-assurance of which he has been accused, the president sounded a note of humility. “America’s influence is not unlimited, but fortunately for the oppressed, America’s influence is considerable, and we will use it confidently in freedom’s cause,” he said. Mr. Bush disavowed the notion that “We consider ourselves a chosen nation” because “God moves and chooses as He wills.”

“There came a day of fire,” Mr. Bush said of September 11, 2001. But in America’s response in Afghanistan and Iraq, the president said, “we have lit a fire as well – a fire in the minds of men. It warms those who feel its power, it burns those who fight its progress, and one day this untamed fire of freedom will reach the darkest corners of our world.”

The president’s speech has a literary precedent. In Fyodor Dostoyevsky’s novel “The Possessed,” Governor von Lembke surveys a town set ablaze by revolutionaries. “The fire is in the minds of men,” he says, “and not in the roofs of houses.” Mr. Bush has surveyed the challenge facing America from global terrorism, and he realizes that meeting the threat isn’t merely a matter of military defenses. “This is not primarily the task of arms,” the president said, in one of the greatest lines of one of the greatest war speeches ever uttered by an American president. America, he was telling the world, will fight fire with a fire of its own.