An article in the Feb. 16 issue of Outlook ("No Room on This Road for a Fragmented Opposition") incorrectly noted when Winston Churchill became Britain's prime minister. It was May 1940, not 1939. Also, the article incorrectly rendered the name of the permanent war crimes court that the United States has refused to endorse. It is the International Criminal Court. (Published 2/21/03)

Democratic government works best when those in power face challenge and debate from opposition politicians, a free press, interest groups and citizens. By responding to critics, the government tests and hones its policies, and wins greater support and legitimacy for them. This is an article of the fundamental American faith. Theoretically at least, we believe in the competition of ideas, and the survival of the best ones.

But a meaningful competition cannot happen without critics and opponents who will confront an administration, effectively question its policies and assumptions, and take their case to the public. In the American system, opposition is not automatic. The party out of power is not required to oppose, and even if it does, there is no guarantee the opposition will be coherent or effective. As the Bush administration has taught us, a determined chief executive -- even one who lost the popular vote but won office in the electoral college -- can roll over opponents like a tank squashing beer cans.

We are experiencing a unique example of that executive power in the Bush administration's campaign against Iraq. The administration put Iraq at the top of its domestic and international agendas, and is preparing to drop the first bombs -- all without benefit of an enemy who struck first, the usual justification for war throughout American history.

As a case study of political opposition, this episode is instructive. Initially, critics of a quick rush to war did affect the administration's behavior. Congress slightly tempered a draft resolution that Bush had sought, limiting any military action to Iraq. More significantly, pressure from Republican elder statesmen, Secretary of State Colin L. Powell and British Prime Minister Tony Blair led Bush to seek a U.N. Security Council resolution before going to war. This delayed action and invited the international community to participate in the debate.

The decision to involve the U.N. has created serious complications for the White House -- Friday's tense Security Council session over whether to give weapons inspections more time is the latest evidence of that -- but it has not derailed the administration's underlying policy. Yesterday's huge anti-war protests around the globe are strong evidence of growing unease, but until the last few weeks, the opposition to war seems to have been largely ineffectual, to the intense frustration of many who share it.

This case study won't be complete for some time, so we cannot yet identify its lessons. If the administration bulldozes ahead, as it seems bent on doing, will it pay a significant price for ignoring its critics at home and abroad who are urging a slower, more deliberate squeeze on Saddam Hussein? Or will it be the critics who are embarrassed by a brief, successful war that unmasks Iraq's weapons of mass destruction with few losses and few long-term negative repercussions?

A few preliminary lessons are already obvious. The first begins with Sept. 11, 2001. Great national trauma produced not opposition, but unity. Traumatized by events they had never imagined, Americans drew together behind their president, and discouraged other politicians from challenging his leadership. President Bush's approval ratings have remained high for 17 months, intimidating his political opposition. In part by exploiting the patriotic themes in vogue since Sept. 11, Bush led his party to unprecedented success in midterm elections, which further demoralized the Democrats.

So opposition has been discouraged, by the spirit of a unified country and by active measures, too. Administration officials deprecate their critics and warn reluctant international institutions that they will become "irrelevant" if they resist war. Some commentators have denounced ordinary citizens who demonstrated in anti-war marches in Washington and elsewhere as dupes of left-wing organizers who despise America. Listen to talk radio and you'll hear vituperative attacks on opponents of war, reminiscent of the Vietnam-era bumper stickers that called on citizens to love America or leave it.

Probably the most important deterrent to effective opposition has been the simple fact that a clear majority of Americans continue to back Bush and favor his plan for military action. After his State of the Union speech and Powell's effective performance at the U.N. ten days ago, the public backed military action by better than 2 to 1, according to the latest Washington Post poll. Support has been growing since Congress overwhelmingly approved a resolution yielding the war-making power entirely to Bush last October, another deterrent to would-be opponents. In the Senate, 29 of 50 Democrats voted to authorize the president to take military action, along with 48 Republicans. The vote was slightly closer in the House, where more than half the Democrats voted no, but 81 Democrats joined 215 Republicans to authorize war.

A second lesson is about presidential power. Partly this is an old one: In matters of war, peace and foreign policy, "the initiative is with the executive," as David Mayhew, a professor of political science at Yale, put it last week. The tools left to Congress are "pretty blunt," said Rep. David Price (D-N.C.), a critic of the administration's policy who nevertheless considers Iraq's weapons of mass destruction a problem that must be dealt with. Price, who is also a political scientist, observed that "we only have one commander in chief. . . . It's not a level playing field [for Congress]. We're not able to be equal partners in shaping policy."

Bush has shown an impressive appetite for the exercise of presidential power right from the start. Scholars and pundits wondered how he would reach out to his opponents after his narrow and controversial electoral victory, but Bush surprised them. He decided to act as though he had won a thumping mandate. He didn't reach out at all, but pushed a huge tax cut through Congress. He appointed a thoroughly conservative Cabinet, including an ardently conservative attorney general. He made a deal with key Democrats that allowed them to take credit for a big education program of a kind that no previous Republican president had embraced.

In the diplomatic arena, the Bush administration announced its preferences on a series of controversial issues, and each time it defied international consensus to assert new American positions: on the Anti-Ballistic Missile Treaty (now dead as a result), on the Kyoto Treaty on global warming (proceeding without the United States), on the International Court of Justice (ditto). Diplomats squealed, but Bush did it his way.

After Sept. 11, the American government effectively decided on the world's response, and the world followed along. Russia, strikingly, used the occasion to transform its foreign policy, aligning itself with the West.

But even as they went along, many American allies were uneasy about this rambunctious, self-confident U.S. government. They feared its "unilateralism" and, more recently, its enthusiasm for war with Iraq. For months, European, Middle Eastern and Asian officials had expressed, more often privately than publicly, their anxieties about the potential consequences of Bush's policy.

Until last week, they proved no more effective than Bush's domestic critics. Now that France and Germany have led the Security Council to put a real political barrier in the president's path, so we will soon learn another lesson: How far can other countries, especially the traditional U.S. allies, push George W. Bush?

In retrospect, Powell's and Blair's success last fall in persuading Bush to go to the U.N. takes on added significance. Frustrated opponents of the administration might pay more attention to this episode. Re-read the speech Vice President Cheney gave to the Veterans of Foreign Wars last August, and you'll see that the vice president had no interest whatsoever in bringing the Iraq issue to the United Nations. Defense Secretary Donald H. Rumsfeld also had made clear his disdain for the U.N. route. But Blair and Powell -- probably aided by public statements by James A. Baker III and Gen. Brent Scowcroft, intimates of Bush's father when he was president -- prevailed. Weeks of negotiations followed, but Powell and the British produced a tough Security Council resolution that preserved multilateralism, at least for a time. But then, Blair is the only leader of a major American ally who unabashedly favors war.

Charles O. Jones, one of the deans of American political science, now retired from the University of Wisconsin, argues that, in the American system, opposition is a misleading word. We don't have a parliament, he notes, where an opposition party challenges the government daily and is always ready with an alternative policy. Instead "we have competition, lots of it -- partisan competition, institutional competition, competition between individuals."

Congressional leaders of the party out of power can't really compete with a sitting president, Jones said in an interview. They can offer competing proposals, but they never have the same stature, or the same ability to dominate the agenda. Jones was one of several political scientists interviewed for this article who said, in effect, don't expect too much from the political opposition to a strong president, at least until the next election, when perhaps their side can prevail.

This seems especially true when the party out of power is the Democrats. The Republicans, since Barry Goldwater's disastrous defeat in 1964, have built a strong conservative party. As the moderate wing has shriveled, the party has become nearly homogenous ideologically, and extraordinarily disciplined. This discipline allowed the GOP to win the House in 1994 for the first time in the modern era, and it has allowed House Republicans to control legislation in their body though their overall majority is tiny. Now Senate Republicans, with a one-vote majority, are showing comparable rigor. This aspect of modern American politics is too little noticed. It sets the Republicans apart, fundamentally, from their disorganized Democratic rivals.

Twelve years of Republican presidents from 1981 to 1993 strengthened the party, and made it more cohesive. But the next eight years under Bill Clinton made no such contribution to the Democrats. They seem as divided, feckless and undisciplined as they were before Clinton ran for president.

Opposition was not something the Founding Fathers encouraged. At first they hoped parties would not become a permanent fixture, though it soon became clear that this was impossible to avoid. Martin Van Buren, the eighth president, was the first to articulate a case for political parties as a force to organize and improve the quality of American politics. He thought parties would provide "a kind of moral discipline, putting a high premium upon loyalty, fidelity, patriotism and self-restraint," in the words of historian Richard Hofstader. Being in opposition was itself a cohesive force, Van Buren believed.

But Van Buren didn't know how the ability to raise money and spend it on modern political technology would turn members of Congress, or presidential candidates, into political entrepreneurs. Politicians not dependent on the party won't naturally demonstrate Van Buren's idea of cohesion.

In the modern context, says Alan Brinkley, a history professor at Columbia, a political opposition can be truly effective only in specific circumstances: When the opposition reflects a large popular movement (anti-war sentiment in the late 1960s and early '70s); when it controls levers of power (the Republican Congress in the Clinton years); when it has a clear and compelling message with which to answer its opponents (presidential candidate Ronald Reagan in 1980, Rep. Newt Gingrich in 1994); or when the leadership discredits itself and is ripe for the picking (Winston Churchill becoming Britain's prime minister in 1939 after the failure of his appeasing Tory colleagues).

"At the moment," said Brinkley, "the Democrats -- and other Bush opponents -- have none of those things."

In all the cases on Brinkley's list, the opponents had a coherent position. They had what specialists now call a "communications strategy" -- a way to speak to the public and to the political audience that was easy to understand. Their opposition was straightforward, usually blunt. Until now, critics and opponents of war in Iraq haven't been able to muster these advantages. Robert Kaiser, associate editor and senior correspondent of The Post, has been reporting from Washington and overseas for four decades.