Bush will be stepping down from office in January after two eventful terms as U.S. leader. He still holds enormous power as chief executive of the U.S. government and as commander in chief of all U.S. military forces. But he lost control of both houses of Congress to the opposition Democrats in the November 2006 midterm elections, and the domestic political focus now in the United States is overwhelmingly on who will succeed him: Republican Sen. John McCain of Arizona or Democratic Sen. Barack Obama of Illinois.

Medvedev only took office in May for the first of what could constitutionally be two four-year terms as president of Russia. But he is widely seen both inside and outside Russia as the front man for his own longtime boss, who handpicked him for the presidency -- former President Vladimir Putin.

Putin still holds the key reins of government in the Kremlin as prime minister and leader of the United Russia faction that dominates the State Duma, the main chamber of the Russian Parliament.

Bush and Putin got on extremely well personally, and they kept relations between what are still the dominant global thermonuclear military powers humming smoothly for most of their first terms in office and beyond. But over the past few years, relations have deteriorated badly.

The Russians are furious at the Bush administration's strong support for the former Soviet republics of Ukraine and Georgia, whose leaders want to join the U.S.-led North Atlantic Treaty Organization. And the Russians also fiercely oppose U.S. plans to build a ballistic missile defense base in Central Europe. Poland was the first choice, but as negotiations with Poland's pro-Russian Prime Minister Donald Tusk drag on, Washington policymakers have started to look at Lithuania, which was invaded by the Soviet Red Army in 1940 and forced to be a Soviet republic for the next 49 years. The Russians are even more furious about that.

Bush and Medvedev took care to get along well personally at their one-on-one meeting on the fringes of the Group of Eight major industrialized nations summit in Japan. And, at least publicly, they presented a common front on dealing with the nuclear programs of North Korea and Iran. Bush also publicly praised Medvedev as "a smart guy," though he took pains to avoid any indication he had looked into his heart, as he once famously said of Putin.

But despite all the efforts at positive spin on both sides, it was clear the two leaders were still at loggerheads over Bush's determination to build a base in Central Europe to house at least 10 Ground-based Mid-course Interceptors capable of destroying any intercontinental ballistic missiles that might be fired by Iran in the future against the United States or Western Europe.

Bush, coming to the end of his two terms in office, cannot guarantee the continuity of his foreign and national security policies beyond January. If McCain wins, he probably will seek to continue many of the same ones, especially maintaining U.S. military forces at a significant level in Iraq and seeking to build the BMD base in Poland or Lithuania. But even then, a Democrat-controlled 111th Congress probably will give him a hard time. If Obama becomes president, he may seek to radically revise both policies.

Medvedev has taken office with the opposite dynamic applying to him. He has taken pains from Day One to emphasize his loyalty and consistency in pursuing the foreign and defense policies shaped by the still ever-present Putin. Western pundits' speculation that Medvedev would prove to be a kinder, gentler leader of Russia than his predecessor have all proven wrong. Bush saw that at first hand in the Monday meeting.

Bush is 20 years older than the boyish, 42-year-old Medvedev. Yet Bush, after nearly eight years in the White House, is losing the power to maintain his legacy while the young Medvedev remains locked into the policies set by Putin and lacks the freedom or the power to strike out in any new directions of his own. Those ironies lay behind the photo opportunity in Japan Monday.