On September 23, 2003, Kofi Annan launched the 58th plenary session of the lately vulnerable behemoth known as the United Nations and warned, “We have come to a fork in the road. This may be a moment no less decisive than 1945 itself, when the United Nations was founded.” Citing the need felt by some (prudently) unidentified nations to unilaterally preempt the threats of terrorism and weapons of mass destruction — as well as a fresh terror campaign against the UN itself — Annan urged “radical changes” in the organization to address the world’s present turmoil and reestablish a priority of peace. The Secretary General pleaded further, “History is a harsh judge: it will not forgive us if we let this moment pass.”

Indeed the very existence, let alone the effectiveness, of the UN has not seemed this endangered since its difficult birth. And, as if on cue, Stephen Schlesinger, director of the World Policy Institute at the New School University in New York City, offers a fully substantiated account of the UN’s formative troubles at the close of World War II in Act of Creation. Schlesinger explains his timing: “I decided to write this book for one reason — to relate the tale of the origins of this unusual organization in order to explain to people in our own time why it must be preserved.”

Oddly enough, Schlesinger doesn’t deliver on his pledge to justify the current survival of the UN, an organization formed in anticipation of a now-defunct cold war. But Schlesinger does carefully unpack the Herculean efforts that fulfilled Franklin Roosevelt’s dream for maintaining universal peace in the aftermath of two devastating world conflicts and specifically dissects the crucial actions taken by a determined State Department of the succeeding Truman administration.

According to Schlesinger, his book is the first full-length account of the pivotal nine-week UN conference launched in San Francisco on April 25, 1945, a long-planned meeting that happened to come just two weeks after Roosevelt’s unexpected death. San Francisco was the ultimate session during which international delegates (including Americans led by a blindsided Truman playing serious catch-up) honed the UN proposals forged at Yalta two months earlier by Roosevelt, Churchill, and Stalin. But more importantly, San Francisco was where key U.S. players roused contentious delegates, namely the Soviets and Latin Americans, to overcome almost insurmountable obstacles to establish history’s greatest collective peacekeeper. For the U.S. architects in San Francisco, the UN would not be a house of cards like Wilson’s League of Nations, but an authoritative base for global tranquility and humanitarian aid.

In Act of Creation, Schlesinger shows that some things change quite a bit, and some never seem to. Gone, of course, are any national alliances with Nazism and the ruthlessness of Stalin. But in 1945, granting UN membership to a Nazi-friendly Argentina — an act pushed by a unified Latin America — was strongly resisted (and understandably so) by our then-ostensible ally, the Soviets. It was a dilemma that caught U.S. negotiators in an awkward place between their wartime principles and a solid regionalism in the West. The democratization of postwar Poland was also a nearly insoluble issue between Stalin and the United States. With the Soviet envoys threatening to abort the San Francisco proceedings entirely as the Polish question dragged on, an exasperated Truman finally relinquished the make-up of the Polish government to an inflexible Moscow. As Truman sighed during the mediations, “There is no UN without Russia.” And then there is the category of timelessness: While the United States was consumed with appeasing the Soviets and Latin Americans, France — with its apparently eternally overblown sense of supremacy — burdened proceedings early by demanding a permanent seat at the Security Council with the “Big Four” military powers (the United States, Great Britain, China, and the Soviet Union).

Act of Creation also showcases two forgotten American engineers of the UN charter and provides intriguing profiles of several influential political figures during their early careers. From Roosevelt, Truman reluctantly inherited his Secretary of State, the now unknown Edward Stettinius. A former businessman, the dashingly handsome Stettinius managed extraordinary diplomacy at San Francisco, despite the fact that Truman believed his chief negotiator “was as dumb as they come.” The unlikely Thomas Jefferson of the UN charter was Russian immigrant Leo Pasvolsky, reputed polymath and State Department special aide. According to Schlesinger, the unassuming Pasvolsky “became the person most responsible for the American language in its UN instrument.” And peppered throughout Act of Creation are alluring portraits of major supporting actors, like a wily Nelson Rockefeller (then Assistant Secretary of State for Latin America), State Department whipping boy Adlai Stevenson (then press secretary and “official leak”), and the shady Alger Hiss (then acting Secretary General of the UN conference).

But the detailed, absorbing record in Act of Creation is not a guide, implicit or otherwise, for overhauling (or even maintaining) the UN today, when the greatest threats to national security are underground and bleed across sovereign borders. Nor is Act of Creation a current rationale for sustaining U.S. involvement in an organization full of members who feel little more than resentment toward the world’s greatest democracy and remaining superpower. There is profound irony, as Schlesinger notes, in the fact that America has become so alienated from an organization that it fought to establish nearly sixty years ago, and Schlesinger implies that the United States must now find “its way back to one of its greatest creations.” But Annan really appears to have it right: it is the UN, more than the U.S., that must catch up with altered times.