Each president of the United States enters office thinking he will be able to define the agenda and set the course of America's relations with the rest of the world. And, almost invariably, each confronts crises that are thrust upon him-wars, revolutions, genocides, and deadly confrontations. Neither Woodrow Wilson nor FDR imagined having to plunge America into world war. Truman had to act quickly, and with little preparation, to confront the menace of Soviet expansion at war's end. JFK, for all his readiness to "bear any burden" in the struggle for freedom, did not expect his struggle to contain Soviet imperial ambitions would come so close to the brink of nuclear annihilation. Nixon was tested by a surprise war in the Middle East. Carter's presidency was consumed by the Shah's unraveling and the Iranian revolution. George H.W. Bush rose to the challenge of communism's collapse and Saddam Hussein's invasion of Kuwait. Clinton squandered the opportunity to stop a genocide in Rwanda and waited tragically too long before stopping one in Bosnia. George W. Bush mobilized the country to strike back after September 11, but, in the view of many, he put most of his chips in the wrong war.

In the eye of the historical storm, and in the absence of a challenge as immediate and overpowering as September 11, Pearl Harbor, or the Nazis' march across Europe, it is risky to identify any set of world events as game-changing. Yet that is what many analysts, including myself, believe the Arab revolutions of 2011 are. And a surprising number of specialists-including hard-eyed realists like Fareed Zakaria-have seized upon the crisis in Libya as a defining moment not just for the United States in the region but for the foreign policy presidency of Barack Obama as well.

To date, one could say that Obama has had a surprisingly good run for a foreign policy neophyte. He has revived the momentum for arms control with a new START treaty with Russia, while pressing the issue of human rights within Russia. He has managed the meteoric rise of China decently, while improving relations with India. He has not cut and run from Iraq-as most Republicans were convinced he would. And he has ramped up but at least set limits to our involvement in Afghanistan. As the Arab revolutions have gathered momentum, he has increasingly positioned the United States on the side of democratic change. His statements and actions have not gone as far as democracy promotion advocates (like myself) would have preferred, but they have overridden cautionary warnings of the foreign policy establishment in the State Department, the Pentagon, think tanks, and so on. Without Obama's artful choreography of public statements and private messages and pressures, Hosni Mubarak might still be in power today.

All of this, however, may appear in time only a prelude to the fateful choice that Obama will soon have to make-and, one fears, is already making by default in a tragically wrong way-in Libya. Why is Libya-with its six million people and its significant but still modest share of global oil exports-so important? Why must the fight against Muammar Qaddafi-a crazy and vicious dictator, but by now, in his capacity for global mischief, a largely defanged one-be our fight?

When presidents are tested by crisis, the world draws their measure, and the impressions formed can have big consequences down the road. After watching Jimmy Carter's weak and vacillating posture on Iran, the Soviets figured he'd sit on the sidelines if they invaded and swallowed Afghanistan. They misjudged, but Afghanistan and the world are still paying the price for that misperception. In the face of mixed messages and a long, cynical game of balance-of-power, Saddam too, misjudged that he could get away with swallowing up Kuwait in 1991. When the United States did not prepare for war as naked aggression swept across Asia and Europe, the Japanese thought a quick strike could disable and knock out the slumbering American giant across the Pacific. When Slobodan Milosevic and his Bosnian Serb allies launched their war of "ethnic cleansing," while "the West"-which is always to say, first and foremost, the United States-wrung its hands, many tens of thousands of innocent people were murdered and raped before President Bill Clinton finally found the resolve to mix air power and diplomacy to bring the genocidal violence to a halt.

If Muammar Qaddafi succeeds in crushing the Libyan revolt, as he is well on his way to doing, the U.S. foreign policy establishment will heave a sad sigh of regret and say, in essence, "That's the nasty business of world politics." In other words: nasty, but not our business. And so: not their blood on our hands. But, when we have encouraged them to stand up for their freedom, and when they have asked for our very limited help, it becomes our business. On February 23, President Obama said: "The United States ... strongly supports the universal rights of the Libyan people. That includes the rights of peaceful assembly, free speech, and the ability of the Libyan people to determine their own destiny. These are human rights. They are not negotiable. ... And they cannot be denied through violence or suppression." Yet denying them through murderous violence and merciless suppression-with a massacre of semi-genocidal proportions likely waiting as the end game in Benghazi-is exactly what Qaddafi is in the process of doing.

Barack Obama has bluntly declared that Qaddafi must go. The Libyan resistance, based in Benghazi, has appealed urgently for the imposition of a no-fly zone. Incredibly, the Arab League has endorsed the call, as has the Gulf Cooperation Council. France has recognized the rebel provisional government based in Benghazi as Libya's legitimate government-while Obama studies this all. Can anyone remember a time when France and the Arab League were ahead of the United States on a question of defending freedom fighters?

There is much more that can be done beyond imposing a no-fly zone. No one in their right mind is calling for putting American boots on the ground in Libya. But we can jam Qaddafi's communications. We can, and urgently should, get humanitarian supplies and communications equipment, including satellite modems for connection to the Internet, to the rebels in Benghazi, where they can be supplied by sea. And we should find a way to get them arms as well. Benghazi is not a minor desert town. It is Libya's second largest city, a major industrial and commercial hub, and a significant port. Through it, a revolt can be supplied. If Benghazi falls to Qaddafi, it will fall hard and bloodily, and the thud will be heard throughout the world.

Time may be running out. As the Los Angeles Times reported yesterday, "All that stands between Kadafi and rebel headquarters in Benghazi are disorganized volunteers and army defectors spread thinly along the coastal highway." They have passion and courage, but they lack weaponry, strategy, and training. Like so many rebel movements, they need time to pull these all together. Time is what a no-fly zone and an emergency supply line can buy them.

Libya's rebels are pleading for our help. "Where is America?" asked one of them, quoted in the L.A. Times, who was manning a checkpoint in Port Brega. "All they do is talk, talk, talk. They need to get rid of these planes killing Libyan people." The "they" he was referring to was the Americans, beginning with their leader-one would hope, still the leader of the "free world"-President Obama.

Many prudent reasons have been offered for doing nothing. It is not our fight. They might lose anyway. We don't know who these rebels really are. We have too many other commitments. And so on. The cautions sound reasonable, except that we have heard them all before. Think Mostar and Srebrenica. And we had a lot of commitments in World War II as well, when we could have and should have bombed the industrial infrastructure of the Holocaust. As for the possibility that the rebels might lose-a prospect that is a possibility if we aid them and a near certainty if we do not-which would be the greater ignominy: To have given Libya's rebels the support they asked for while they failed, or to have stood by and done absolutely nothing except talk while they were mowed down in the face of meek American protests that the Qaddafi's violence is "unacceptable"?

Oh yes. There is also the danger that China will veto a U.N. Security Council Resolution calling for a no-fly zone. Part of us should hope they do. Let the rising superpower-more cynical than the reigning one ever was-feel the first hot flash of hatred by Arabs feeling betrayed. Go ahead, make our day.

Presidents do not get elected to make easy decisions, and they certainly never become great doing so. They do not get credit just because they go along with what the diplomatic and military establishments tell them are the "wise and prudent" thing to do. This is not Hungary in 1956. There is no one standing behind Qaddafi-not the Soviet Union then, not the Arab League now, not even the entirety of his own army. That is why he must recruit mercenaries to save him. Qaddafi is the kind of neighborhood bully that Slobodan Milosevic was. And he must be met by the same kind of principled power. For America to do less than that now-less than the minimum that the Libyan rebels and the Arab neighbors are requesting-would be to shrink into global vacillation and ultimately irrelevance. If Barack Obama cannot face down a modest thug who is hated by most of his own people and by every neighboring government, who can he confront anywhere?

For the United States-and for Barack Obama-there is much more at stake in Libya than the fate of one more Arab state, or even the entire region. And the clock is ticking.

The first decade of the 21st century has seen a dramatic reversal of fortune in the relative prestige of different political and economic models. Ten years ago, on the eve of the puncturing of the dotcom bubble, the US held the high ground. Its democracy was widely emulated, if not always loved; its technology was sweeping the world; and lightly regulated "Anglo-Saxon" capitalism was seen as the wave of the future. The United States managed to fritter away that moral capital in remarkably short order: the Iraq war and the close association it created between military invasion and democracy promotion tarnished the latter, while the Wall Street financial crisis laid waste to the idea that markets could be trusted to regulate themselves.

China, by contrast, is on a roll. President Hu Jintao's rare state visit to Washington this week comes at a time when many Chinese see their weathering of the financial crisis as a vindication of their own system, and the beginning of an era in which US-style liberal ideas will no longer be dominant. State-owned enterprises are back in vogue, and were the chosen mechanism through which Beijing administered its massive stimulus. The automatic admiration for all things American that many Chinese once felt has given way to a much more nuanced and critical view of US weaknesses - verging, for some, on contempt. It is thus not surprising that polls suggest far more Chinese think their country is going in the right direction than their American counterparts.

But what is the Chinese model? Many observers casually put it in an "authoritarian capitalist" box, along with Russia, Iran and Singapore. But China's model is sui generis; its ­specific mode of governance is difficult to describe, much less emulate, which is why it is not up for export.

The most important strength of the Chinese political system is its ability to make large, complex decisions quickly, and to make them relatively well, at least in economic policy. This is most evident in the area of infrastructure, where China has put into place airports, dams, high-speed rail, water and electricity systems to feed its growing industrial base. Contrast this with India, where every new investment is subject to blockage by trade unions, lobby groups, peasant associations and courts. India is a law-governed democracy, in which ordinary people can object to government plans; China's rulers can move more than a million people out of the Three Gorges Dam flood plain with little recourse on their part.

Nonetheless, the quality of Chinese government is higher than in Russia, Iran, or the other authoritarian regimes with which it is often lumped - precisely because Chinese rulers feel some degree of accountability towards their population. That accountability is not, of course, procedural; the authority of the Chinese Communist party is limited neither by a rule of law nor by democratic elections. But while its leaders limit public criticism, they do try to stay on top of popular discontents, and shift policy in response. They are most attentive to the urban middle class and powerful business interests that generate employment, but they respond to outrage over egregious cases of corruption or incompetence among lower-level party cadres too.

Indeed, the Chinese government often overreacts to what it believes to be public opinion precisely because, as one diplomat resident in Beijing remarked, there are no institutionalised ways of gauging it, such as elections or free media. Instead of calibrating a sensible working relationship with Japan, for example, China escalated a conflict over the detention of a fishing boat captain last year - seemingly in anticipation of popular anti-Japanese sentiment.

Americans have long hoped China might undergo a democratic transition as it got wealthier, and before it became powerful enough to become a strategic and political threat. This seems unlikely, however. The government knows how to cater to the interests of Chinese elites and the emerging middle classes, and builds on their fear of populism. This is why there is little support for genuine multi-party democracy. The elites worry about the example of democracy in Thailand - where the election of a populist premier led to violent conflict between his supporters and the establishment - as a warning of what could happen to them.

Ironically for a country that still claims to be communist, China has grown far more unequal of late. Many peasants and workers share little in the country's growth, while others are ruthlessly exploited. Corruption is pervasive, which exacerbates existing inequalities. At a local level there are countless instances in which government colludes with developers to take land away from hapless peasants. This has contributed to a pent-up anger that explodes in many thousands of acts of social protest, often violent, each year.

The Communist party seems to think it can deal with the problem of inequality through improved responsiveness on the part of its own hier­archy to popular pressures. China's great historical achievement during the past two millennia has been to create high-quality centralised government, which it does much better than most of its authoritarian peers. Today, it is shifting social spending to the neglected interior, to boost consumption and to stave off a social explosion. I doubt whether its approach will work: any top-down system of accountability faces unsolvable problems of monitoring and responding to what is happening on the ground. Effective accountability can only come about through a bottom-up process, or what we know as democracy. This is not, in my view, likely to emerge soon. However, down the road, in the face of a major economic downturn, or leaders who are less competent or more corrupt, the system's fragile legitimacy could be openly challenged. Democracy's strengths are often most evident in times of adversity.

However, if the democratic, market-oriented model is to prevail, Americans need to own up to their own mistakes and misconceptions. Washington's foreign policy during the past decade was too militarised and unilateral, succeeding only in generating a self-defeating anti-Americanism. In economic policy, Reaganism long outlived its initial successes, producing only budget deficits, thoughtless tax-cutting and inadequate financial regulation.

These problems are to some extent being acknowledged and addressed. But there is a deeper problem with the American model that is nowhere close to being solved. China adapts quickly, making difficult decisions and implementing them effectively. Americans pride themselves on constitutional checks and balances, based on a political culture that distrusts centralised government. This system has ensured individual liberty and a vibrant private sector, but it has now become polarised and ideologically rigid. At present it shows little appetite for dealing with the long-term fiscal challenges the US faces. Democracy in America may have an inherent legitimacy that the Chinese system lacks, but it will not be much of a model to anyone if the government is divided against itself and cannot govern. During the 1989 Tiananmen protests, student demonstrators erected a model of the Statue of Liberty to symbolise their aspirations. Whether anyone in China would do the same at some future date will depend on how Americans address their problems in the present.

The writer is a fellow at the Freeman Spogli Institute for International Studies at Stanford University. His latest book, The Origins of Political Order, will be published in the spring.

On January 18, the Honorable Bob Rae, Liberal Member of Parliament for Toronto Centre and the foreign affairs critic for the Liberal Party of Canada was the featured speaker at a special CDDRL seminar. Rae addressed the Stanford community on the topic of his latest book Exporting Democracy, published in November 2010 by McClelland & Stewart. CDDRL Deputy Director, Kathryn Stoner, welcomed Rae to Stanford and Ben Rowswell, Visiting Scholar and Canadian "diplomat in residence," introduced the distinguished Rae stressing the timeliness of this topic.

This occasion marked the debut of Rae's book to a US audience and drew a sizable crowd interested in learning more about the MP's views on the role of Western powers in statebuilding and democracy promotion efforts abroad. Based on his personal experience engaging in diplomatic missions in Iraq, Afghanistan, Sri Lanka, and across the Middle East, Rae was confronted with the limits of power and democratic ideals in foreign lands.

 His discussion focused on the theoretical and practical analysis of the role of democracy in statebuilding that is the foundation of his argument in Exporting Democracy. Drawing  on the writing of 18th century philosophers, Thomas Paine and Edmund Burke, Rae examined the tensions between natural law and justice versus customs and tradition that continue to dominate the debate in modern day statecraft.

 Rae's experience observing democracy promotion abroad allowed him to recognize the importance of upholding democratic values, while also respecting the idea that democracy cannot be viewed as the "gold standard" for all. "From a Western perspective the debate suffers from the notion that the idea of democracy has emerged as perfectly natural and an automatic assumption of our daily lives. In reality it has generally been accompanied by periods of great conflict and can take hundreds of years to bear fruit as evidenced by the American and Canadian experience."

Rae emphasized that the best way Western countries can promote democracy is by helping other countries develop their own solutions to their own problems. 

Rae's sensitivity to the consequences of Western interventions, his belief in the principles of human rights, and his testimony to the importance of humility and pragmatism in our efforts of statebuilding abroad, offered the Stanford community a new perspective on the effectiveness of the global democracy movement.