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....

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.