The talks not only brought a close to Europe’s bloodiest conflict since the time of the Nazis. As I point out in my latest book, 1995: The Year the Future Began, the diplomatic success at Dayton also “revived a spirit of ‘American Exceptionalism’ and launched the United States on a trajectory of increasingly forceful interventions abroad.”

For several years after Dayton, U.S. foreign policy was characterized by a sense of hubris and muscularity, the consequences of which the country is still sorting through.

The talks began November 1, 1995, at the sprawling Wright-Patterson Air Force base  just outside Dayton, and brought together the leaders of Bosnia, Croatia, and Serbia  — the warring factions in a conflict that began more than three years earlier, amid the post-Cold War breakup of the former Yugoslavia.

For nearly three weeks the talks went on, often teetering on collapse. Indeed, failure seemed assured on the morning of November 21, 1995, when the U.S. delegation, led by Richard C. Holbrooke, an assistant secretary of state, began what was to be its close-out meeting. But the Balkan leader most eager for a deal at Dayton, Serb President Slobodan Milosevic, showed up and proposed an 11th hour gambit to save the talks, which were hung up on the administrative division of Bosnian territory.

They specifically were hung up on which side would control Brcko, a strategic river town in northern Bosnia on the Croatian border. Milosevic, who had insisted that the Bosnian Serbs control the town, relented and suggested its sovereignty be decided by international arbitration.

Milosevic’s gambit, which is colorfully recounted in Derek Chollet’s book, The Road to the Dayton Accords, removed the final obstacle to a complicated peace settlement. The Croats and Bosnians agreed to international arbitration for Brcko, and the Dayton accords were initialed that afternoon. They were formally signed in Paris a few weeks later.

Diplomatic success at Dayton gave rise to an interlude of American muscularity, both diplomatically and militarily — an interlude marked by a willingness to take the lead, a willingness to apply military force, and a willingness to sidestep or ignore the United Nations in doing so. That interlude was marked by the expansion of what Peter Beinart has accurately termed a “hubris bubble,” which grew during the late 1990s and in the early years of the 21st century.

The “hubris bubble” swelled when the Clinton administration bombed Iraq in 1998, to degrade the country’s suspected arsenal of weapons of mass destruction, swelled when the administration bombed Serbia in 1999, to force Milosevic to yield control of the province of Kosovo. It swelled when, following the deadly terrorist attacks of September 11, 2001, the United States invaded Afghanistan to topple the Taliban regime and dismantle the al-Qaeda network that carried out the attacks. It swelled still more in 2003, the United States led an invasion of Iraq to overthrow the regime of Saddam Hussein, which was suspected of stockpiling weapons of mass destruction.