Will the 21^st century be defined by great power war or peace? By prosperity or poverty? The answers depend largely on the course set by Washington and Beijing.

The script for the Party Congress hasn’t been revealed, but I am betting that Xi Jinping will not only be “re-elected” to a second five-year term as the party’s general secretary and China’s president, but also that he will effectively be crowned China’s 21st-century emperor.

President Trump is expected to announce today or tomorrow that he is taking the first step to bury the Iran nuclear deal. That 2015 agreement pushed Iran’s nuclear program back from a few months away from a bomb to over a year. By “decertifying” the deal, Trump will hand the ball to Congress, inviting it to reimpose sanctions on Iran. That would mean, in effect, unilateral American withdrawal from the agreement, freeing Iran from its current constraints and allowing it to resume its quest for a bomb.

Amid the exchange of threats between North Korea and the United States, ongoing North Korean nuclear and missile tests, and U.S. talk of “all options,” there is growing concern about the real possibility of war with North Korea. What many have not yet reckoned with is an even darker specter. Could events now cascading on the Korean Peninsula drag the U.S. and China into a great-power war?

• Alexey Arbatov warns that nukes will end up in hands of terrorists sooner or later.
• Belfer Center experts build timeline for Nunn-Lugar in former Soviet Union.
• Graham Allison calls for U.S.-Russian cooperation on counter-proliferation.
• U.S. and Russian experts weigh in on nuclear threats posed by North Korea.
• Hecker and White call for revival of U.S.-Russian lab-to-lab cooperation.

The United States and China have reached a precarious moment in their relationship. Ensuring a peaceful outcome will be the greatest geopolitical challenge of the twenty-first century. Are our leaders up to it?

From the moment that President Barack Obama told President-elect Donald Trump during the transition about the impending threat of North Korean nuclear-tipped ICBMs, Trump’s basic stance has been: not on my watch. From his tweet of January 2 (“won’t happen!”) to his August statements that the U.S. military is “locked and loaded” to unleash “fire and fury” on North Korea if it threatens America, Trump has sought to draw a red line that makes it clear he will do whatever is necessary to halt North Korea’s nuclear and missile programs—before they can target the continental United States.

Graham Allison, Director of Harvard's Belfer Center for Science and International Affairs from 1995 until July 2017, is a leading analyst of US national security and defence policy. His latest book, 'Destined for War: Can America and China Escape Thucydides’s Trap?', was published by Houghton Mifflin Harcourt in May 2017, and is the subject of this interview, conducted via email over the course of the last few weeks.

President Trump appears desperate, erratic and even irrational as he struggles to stop North Korea from developing nuclear weapons capable of reaching the U.S. mainland. If the president is to be believed, he stands ready to run any risk, pay any price and do whatever necessary to keep the U.S. safe. This includes launching a pre-emptive attack that risks dragging America and China into a second Korean War. To understand the method in what looks like madness, recall the Cold War strategy known as “nuclear chicken.”

As Americans awaken to a rising China that now rivals the United States in every arena, many seek comfort in the conviction that as China grows richer and stronger, it will follow in the footsteps of Germany, Japan, and other countries that have undergone profound transformations and emerged as advanced liberal democracies. In this view, the magic cocktail of globalization, market-based consumerism, and integration into the rule-based international order will eventually lead China to become democratic at home and to develop into what former U.S. Deputy Secretary of State Robert Zoellick once described as “a responsible stakeholder” abroad.