One hundred years ago, at 3:47 p.m. on Sept. 5, 1905, the American presidency became a global institution. That is the precise moment when the Treaty of Portsmouth was signed, ending the Russo-Japanese War and bringing enormous credit to the treaty's architect, Theodore Roosevelt. For single-mindedly willing it into existence, Roosevelt won the Nobel Peace Prize -- the only time a sitting American president has done so. Today, we are a far stronger nation in nearly every category than we were then -- five states bigger, about four times as populous, trillions richer. Yet we are failing badly in precisely the area of achievement -- peacemaking -- that brought Roosevelt the acclamation of the world.

The nasty conflict that erupted at the intersection of Russian and Japanese ambitions in 1904 has been largely forgotten in this country, but in many ways it set the tone for the 20th century. It foreshadowed the rise of Japan and the demise of imperial Russia, which passed each other like riders on up and down escalators. It hinted at the coming devastation of World War I and the Russian Revolution. And it suggested trouble ahead for all nations with interests in the Pacific theater -- including the United States. On Dec. 7, 1941, Japan's lead carrier flew the command flag from the 1905 campaign as it steamed toward Pearl Harbor.

But the Treaty of Portsmouth also offered a happier message, and said something tremendously important about the power of the United States to resolve distant wars through diplomacy. The piece of paper signed that day proved that even the most intractable conflicts have endings, and that presidents are often gifted at finding them. Roosevelt had that gift, and the Nobel prize that symbolizes it now sits on the mantle of the West Wing's Roosevelt Room, adjacent to the Oval Office. It is surprisingly small -- a golden hockey puck -- and yet the entire room revolves around it.

The world of a hundred years ago -- though, of course, much different from today's -- offered certain geopolitical parallels. Then as now, Russia was a gigantic nation seeking to define its place in Europe and Asia. Japan was a formidable regional power adapting brilliantly to a new economic order, that which stemmed from the industrial revolution. Their war broke out in 1904 because of overlapping aspirations in northeastern China and Korea, where each sought access to strategic railways and Pacific ports. The Russians were thrashed in the early battles, causing embarrassment for Czar Nicholas II. Yet the Japanese were worried by the vastness of their adversary and the cost of maintaining a large military effort far from home.

Despite the war's remoteness from U.S. shores, Roosevelt grew more and more attentive to its diplomatic clatter and the growing urgency of ending this corrosive conflict. It was a favorable moment to jump into the ring: Still basking in the afterglow of the 1904 election, which confirmed his legitimacy after William McKinley's 1901 assassination, he enjoyed a rare confidence on the world stage.

Few presidents ever came to office with a deeper knowledge of foreign affairs, and he had added to his reputation with a series of bold initiatives in his first few years -- articulating a more active U.S. policy toward Latin America, clearing the way for the stalled Panama Canal, arbitrating a dangerous debt crisis between Germany and Venezuela. He maintained constant contact with the jockeying powers of Europe, deepening the sense that the United States was a fair broker of their incessant disputes.

Roosevelt urged a peace conference between the Russians and the Japanese, and as the bloody conflict drained both combatants, they grudgingly responded. Deciding the details -- when, where and how it would happen -- was enormously complicated. But eventually, it was agreed that the United States would host delegations from each country in August 1905.

Since Washington was unbearably hot and humid in the late summer, Roosevelt decided to send them all to a "cool, comfortable and retired place" -- the naval base in Portsmouth, N.H.

Peace negotiations turned out to be nearly as difficult as the war. Enormous obstacles stood in the way of a treaty, including Japan's insistence on being granted the huge island of Sakhalin and a healthy indemnity. Following the talks closely from Washington, Roosevelt wrote a friend that he wanted to "knock their heads together." At one point, the negotiators spent eight minutes smoking cigarettes, glaring at each other without saying a word.

Though he himself never set foot in Portsmouth, Roosevelt drove talks forward with an invisible riding crop. Relentlessly, he sent letter upon letter imploring the parties to do more and summoned stubborn negotiators to visit him at his summer White House in Oyster Bay, N.Y. His acute grasp of the situation perfectly offset his refreshing disdain for diplomatic protocol. He even received one envoy in his tennis clothes -- an amazingly daring act in those nearly Victorian times.

In truth, though, each side secretly wanted peace, and the envoys worked creatively -- often beyond their instructions -- to make it a reality. Finally, the impossible: The Japanese withdrew their request for money, and the Russians agreed to cede the southern half of Sakhalin. The treaty was signed before either side could reconsider. That it was unpopular in both countries was a perfect measure of its balance.

From around the world, accolades poured in. Kaiser Wilhelm of Germany wrote "the whole of mankind must unite and will do so in thanking you for the great boon you have given it." His enthusiasm was justified, for the treaty signaled a vitally important breakthrough. If President McKinley's orgy of conquest in 1898 -- the year the United States annexed Guam, Puerto Rico and the Philippines -- had presented Americans as a people willing to fight for foreign territory, 1905 offered a starkly new perspective. Without signaling a lessening of the country's global ambition -- Roosevelt was never the retiring type -- it showed that Americans also felt the confidence to roll up their sleeves and do the hard work of peace.

And so a tradition was born. Woodrow Wilson dominated the peace process at Versailles in 1919, driving the balky negotiations forward with his force of personality and his disdain for the failures of European diplomacy. Near the end of World War II, Franklin Roosevelt designed a new system of peace arbitration -- the United Nations -- as he led the military effort that effectively destroyed the old power arrangement. Jimmy Carter cobbled together a historic peace between Egypt and Israel in 1978. Bill Clinton's herculean labors were not always successful, but still netted the Arafat-Rabin handshake on the South Lawn, the Wye and Camp David summits, and the Good Friday accord in Northern Ireland.

All these efforts, including the failures, enhanced the office's prestige, framing each president as more than the head of a single country. Over the years, we got used to the image of foreign leaders trying to look relaxed at Camp David as they debated details for ending conflicts thousands of miles away. Each success reminded us that there are other ways to measure national grandeur than GDPs and missile throwweights. Any strong nation can win a war. It takes a great nation to win a peace.

The 21st century is still young, but it does not appear to favor the tradition of presidential peacemaking. In the biggest negotiations of the moment, the United States is either absent or unpopular. With Iran, where the world would like to see a great deal less nuclear activity, the heavy lifting has been done by France, England and Germany. With North Korea, the United States has refused close negotiations in favor of a more rigid six-party arrangement. With the Middle East, the last parley at Camp David was held five long years ago, in the summer of 2000. President Bush's famous road map for peace seems to be locked in the glove compartment.

McKinley was said to be a hero to the president during Bush's first term. Might McKinley's successor now provide a model for the remainder of the second term? With Iraq absorbing much of the world's attention, it would be politically astute for the United States to return to the peace table that we occupied with such distinction in the 20th century. There is no better place to begin than in the hardest place of all: the Middle East. And there is no better time than the present: post-Gaza, post-Katrina and with only three years left on this president's watch. On the centennial of Teddy Roosevelt's best day, perhaps we can channel the spirit of this Republican ancestor to salvage our damaged pride, and restore the world's faith in a better kind of American intervention.

Author's e-mail:

Ted Widmer directs the C.V. Starr Center for the Study of the American Experience at Washington College in Chestertown, Md.

Force of personality: The Treaty of Portsmouth, ending the Russo-Japanese War, came about largely because of Theodore Roosevelt (above with Russian and Japanese delegates aboard the Mayflower in 1905). He understood that power comes from making peace as much as from making war, the author argues. At left, Roosevelt reviews the Norwegian Navy in Christiansted, when he traveled there in 1910 to receive the Nobel Peace Prize for his efforts in securing the treaty.