Last March -- long before the events of Sept. 11 -- President Bush spent part of a weekend at Camp David reading a book called "Eastward to Tartary," a political travelogue through the little-known but volatile region stretching from Romania and Bulgaria to the shores of the oil-rich Caspian Sea.

Bush immersed himself the book, which described a realm haunted by the specter of conflict over Caspian pipelines, war between Iran and Azerbaijan, instability in Syria, chaos in Georgia, and stagnation in Romania and Bulgaria. The book, more conversational than the analytical briefings from the diplomatic community, meshed with his evolving view of the world. He asked his staff to invite the author to the White House.

Bush's interest in the book -- and the somber views of its author, Robert Kaplan -- reveals something about the intellectual journey of a president who nearly a year later is consumed with a campaign against "evildoers" and the dangers posed by the "axis of evil." Though Sept. 11 may have altered Bush's presidency, it probably didn't fundamentally alter his view of the world as a place populated by complicated, ancient feuds and dozens of dangerous groups. These groups must be confronted and, if necessary, vanquished, Bush has made clear.

Or as Kaplan wrote, "The human landscape is grim, but great powers throughout history faced grim landscapes and were not deterred from pursuing their goals." How should a great power respond? According to Kaplan, with "leaders who know when to intervene, and do so without illusions."

This worldview was probably little more than a gut feeling for candidate Bush, but over the past year -- under the tutelage of national security adviser Condoleezza Rice, discussions with visitors such as Kaplan and some on-the-job training -- it has acquired more definition. Because it stresses the hatred and ambition of "evildoers," it stands in stark contrast to the outlook of his father as well as former president Bill Clinton, both of whom stressed nations' self-interests in achieving freedom and prosperity. Bush senior may have waged war against Iraq, but throughout his career he placed greater faith in diplomacy than in confrontation. And Clinton, partly in the afterglow of the fall of the Soviet Union, mostly promoted a positive vision of a world where "democratic enlargement" and free trade would spread stability and liberal values.

Bush's darker view -- which the events of Sept. 11 reinforced -- is now driving U.S. policy on everything from civil liberties to federal spending to foreign policy. Military spending is projected to outstrip non-military discretionary spending within a few years. Extraordinary detention procedures are followed for terrorism suspects, especially those who are not U.S. citizens. Countries with whom relations have been tense are asked to choose sides. In a battle against the forces of darkness, it's dangerous to remain in the shadows.

Bush's stark view of the world does not appear to weigh him down so much as give him a clear sense of mission. That was Kaplan's conclusion after his hour-long discussion with Bush last March. "I think Bush's view of the world is that America's predominance is tenuous,"he says now. "The world is a bad place with a lot of bad people who can do us harm and the most important moral commitment for America is to preserve its power."

Bush had plenty of other things on his agenda the day of Kaplan's visit. The president was to meet the Japanese prime minister to smooth over the accidental sinking of a Japanese fishing boat by a U.S. submarine. Later that week, touting a policy of "realism," the administration would reproach a Chinese vice premier over religious freedom and expel dozens of Russian diplomats in a tit-for-tat over espionage allegations.

But first, Bush wanted to discuss "Eastward to Tartary," a sequel to Kaplan's influential "Balkan Ghosts," a sobering political history that Clinton's aides said he read before deciding not to intervene in Bosnia. Bush, soon to embark on his first presidential visit to Europe, wanted to hear what Kaplan had to say about the stability of Romania and Bulgaria. "Tell us what you think, that's why you're here," Bush said. For 45 minutes, he and Kaplan talked, while Rice, NSC director of European affairs Daniel Fried and White House chief of staff Andrew Card mostly listened.

Bush said he wanted to increase stability in the region described in Kaplan's book, but he sounded cautious about getting too deeply involved in certain places, according to Kaplan. Bush told Kaplan that he had to be careful of entanglements because no one could predict where future threats would come from.

One of those threats has since become a reality, and Kaplan's writing helps explain Bush's response. In an article published this fall in the National Interest, written before the terrorist attacks, Kaplan predicted that international law would play a smaller role in conflicts as wars became increasingly unconventional and undeclared. He argued that in facing adversaries unconcerned with civilian casualties, "our moral values . . . represent our worst vulnerabilities." Democratic consultation, he said, would become impractical in situations that called for quick responses to outrages.

Is there a better description of the situation the Bush administration found itself in after the attacks? Terrorists had taken advantage of America's free society to infiltrate it and do it monstrous harm. And, perhaps to their surprise, the administration's swift military response showed moderate concern but not undue anxiety about civilian casualties, international law, or consultation with Congress. Instead, Bush gave his defense secretary and CIA director broad freedom to do whatever was necessary in the campaign in Afghanistan to "smoke 'em out."

But unlike Kaplan, who has written a new book about why leadership in an age of warrior politics demands a "pagan ethos" similar to that of the ancient Greeks or Romans, Bush's rhetoric on America's new war is partly religious. "We've come to know truths that we will never question: Evil is real, and it must be opposed," he said in his State of the Union address. Americans were "facing danger together," he said, and "many have discovered again that even in tragedy -- especially in tragedy -- God is near."

For most foreign policy experts, who prefer to talk in terms of values and interests, Bush lacks nuance. On the other hand, when Ronald Reagan called the Soviet Union an "evil empire," that sounded more naive and rash at the time than it does in retrospect. And how one looks at Bush's rhetoric depends on whether one thinks it is supposed to demonstrate sophistication, or mobilize Americans, or send a message abroad.

Bush's zeal and willingness to do battle with the forces of darkness is a surprise to many Republicans, especially those who thought his foreign policy approach would more closely resemble his father's. "He's different from his father in this regard. His father knew the world intimately, knew the people, had huge background. This president doesn't have that, but his political instincts are good," a senior Republican said last May. The senior Republican, who spoke on background, said Bush the younger was a "huge admirer" of Bush senior, and would ultimately adopt similar policies, set aside unilateralist talk, contain but not oust Saddam Hussein, get involved in the Middle East conflict, reach out to Iran and reconstruct damaged relations with China.

Only on China has Bush the younger come around to his father's less confrontational approach. Even there, the conversion is shaky. Unlike Russia, clearly an ally in the war on terrorism and a partner in trying to control proliferation, China is in a tenuous position with Bush. Its sales of weapons and technology to countries such as Pakistan and Iraq do not sit well with a president who says there is "no middle ground."

In a black-or-white world, a war on terrorism becomes a war of morality. The consequences of such a war -- civilian casualties, pacts with repressive regimes such as the one in Uzbekistan, prisoners in a legal limbo -- can be seen as necessary byproduct of this moral mission. And if that makes some of us uncomfortable, Bush would say that the greater goal is to drive the barbarians away from the gates of the civilized world, and the United States in particular.

In this context, a war on evil can become a war without end. In turning to the "axis of evil," Bush is targeting something broader than terrorism in the traditional sense. Of the three countries that Bush has included in his axis, two -- Iraq and North Korea -- have shown little involvement with terrorism in recent years. The definition of our foe has been broadened, so that evil can mean an irrational actor such as Osama bin Laden as well as North Korea's scary but arguably rational leader Kim Jong Il. Iran's modern, if somewhat democratic, society is lumped together with the North Korean hermit state.

What are the politics of an endless war on evil? George W. Bush has always fancied himself a better politician than his father. And while national security issues are undoubtedly foremost in his mind, the political dimensions must be calculated somewhere in the White House. Perhaps whoever is doing that is thinking that the mistake Bush's father made was to end the Persian Gulf War too early. Not a week or two early, as some critics allege, but two years early. Maybe Bush senior never should have declared victory at all.

Many Republicans criticized the Clinton administration for entering peacekeeping operations without having an exit strategy. It's ironic, perhaps, that this administration seems to be waging war without any exit strategy other than moving to the next battlefield. The war could become, as in the Orwell novel "1984," a permanent state of being. "War is Peace," the Ministry of Truth slogan read in the novel.

Or, as Kaplan has argued, war becomes a condition no longer distinctly separate from peace. Bush has embraced that view, at least for now. As he declared in his State of Union address, "I will not wait on events, while dangers gather." He has seen a grim landscape, to paraphrase Kaplan, and seems determined to confront it.

Steven Mufson, an assistant Outlook editor, covered foreign policy for The Post from 1999 to 2002.