What about 2014? Can we sketch a scenario today that could sleepwalk to war? Fortunately, not easily. Of course, there could well be incidents in or over the South or East China Sea in which US and Chinese warships or aircraft collide. Recall, this occurred in 2001 near Hainan Island, when a hotrodding Chinese pilot caused a U.S. spycraft to make an emergency landing in China. Tense moments ensued, but both governments contained themselves and the crisis was resolved. Recently a Chinese ship in the South China Sea would have rammed an American warship had the US captain not changed course at the last minute. While playing chicken with military ships and aircraft is foolish, both the US and China have "wargamed" these possibilities so thoroughly that it is reasonable to expect adult supervision before matters get out of hand.

More problematic are potential confrontations between Japan and China. Japan is America's principal ally in Asia, and the US-Japan Mutual Defense Treaty commits the US to come to its defense. Whether knowingly or unwittingly, when the US returned Okinawa to Japan in 1972, it included a string of largely unknown islands in the East China Sea called the Senkakus. On Chinese maps, these are named the Diaoyus, and China claims them as its own.

Historically, one of the surest predictors of hostility between nations are territorial disputes. (Japan and Russia have still not signed a peace treaty for the war that ended in 1945 because the Russians control four islands the Japanese regard as theirs.) Claims about others seizing "our territory" stir nationalistic passions in autocracies and democracies alike. Moreover, as the Austro-Hungarian case demonstrates vividly, nations in decline feel increasingly insecure and become more susceptible to fantasies that promise to restore their rightful place by a bold stroke.

For Japanese, the last twenty years are "lost decades" of economic stagnation and national decline in which China overtook and then displaced them as the second largest economy in the world. Japan's Prime Minister Abe came to power determined to revive economic growth at home and respect for Japan abroad. By radical changes in Japanese monetary policy, including its own version of quantitative easing, decades of disinflation have been reversed, and Japan's economy is showing modest signs of recovery. Abe's grander ambitions, however, are to rebuild Japan's military power, revise what many Japanese see as a US-imposed peace treaty that ended World War II, significantly increase Japan's defense spending, and demonstrate that Japan can stand up to defend its own territory.

Thus my most likely scenario for war in 2014 would begin with initiatives like China's recent unilateral declaration of an exclusive air zone over the islands in the East China Sea that trigger escalatory responses by Japan leading to the downing of a plane or sinking of a ship with scores of casualties. There could follow a process of retaliatory risk-taking in which each responds to the other, producing a small naval and air conflict between Japan and China at sea in which dozens of ships and planes are destroyed. Expecting the US Navy and Air Force to have its back, and certain that together, Japanese and US military forces currently have decisive superiority, Japanese politicians could adopt a strategy of "tit +" for "tat" and expect China to back down.

Students of decisions by the regime that has governed China since 1949 would not be so sure. As Taylor Fravel’s analysis of Chinese uses or force in territorial disputes over the past six decades finds, in cases where they were unambiguously militarily weaker than their opponent, China has been three times as likely to go to war as in cases in which they had the upper hand. Americans should recall the Korean War where a Chinese Communist regime that had not yet even consolidated control over its core entered the war as the US marched just south of the Yalu, fought the US back to the 38th parallel, and forced the US to settle for an armistice.

Will 2014 bring another Great War? My bet is almost certainly not, but with a note of caution. Claims that war is "inconceivable" are not statements about what is possible in the world, but rather, about what our limited minds can conceive. The fact that Presidents Obama and Xi understand that war would be folly for both China and the US is relevant but not dispositive. None of the leaders in Europe of 1914 would have chosen the war they got and that in the end they all lost. By 1918, the Kaiser was gone, the Austro-Hungarian Empire dissolved, the Tsar overthrown by the Bolsheviks, France bled for a generation, and England shorn of the flower of its youth and treasure. Given a chance for a do-over, none of the leaders would have made the choices he did.

Thus as we look forward with hope to the year ahead, reflection on mistakes made a century ago reminds us of the perils of complacency.

Graham Allison is Director of the Harvard Kennedy School’s Belfer Center for Science and International Affairs.

Image: U.S. Air Force/Flickr.

Editor's Note: The following article has been updated since publication.

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