The personal touch is sometimes a pivotal item in the diplomatic toolbox. President Bush and Russian President Vladimir Putin, time and again, have reached for just the thing to improve one of the world's most crucial partnerships.

A grinning Putin once put Bush behind the wheel of his prized 1956 Volga at his dacha outside Moscow. Bush has brought Putin to the Camp David presidential retreat in Maryland. He made Putin the first head of state to visit his Texas ranch, entertaining the Russian leader with square dancing.

At a lavish Red Square military parade in Moscow celebrating World War II's victory, Putin saved the seat closest to him for Bush and risked alienating other world leaders by grandly terming the American his guest of "special importance" above all the others.

Now, for less than 24 hours starting Sunday afternoon, the U.S. president is hosting his Russian counterpart at the Bush family's stone-and-shingle summer home on the craggy Maine coast. No other leader has received such a rarified invitation.

The Russian leader gets two presidents in one visit: Bush's dad, former President George H.W. Bush, owns the home and is playing low-key host to the meetings. Putin also will be feted with spectacular views, sparkling New England summertime weather, lobster at nearly every meal, and possibly a striper fishing excursion on the elder Bush's speedboat.

"You only invite your friends into your house," Bush said in November 2001, when Putin came to Crawford, Texas.

But six years of gestures from the extravagant to the odd have not masked or solved the problems that increasingly dog U.S.-Russian relations. Observers say the alliance lately has reached its lowest point in recent memory and they were skeptical that what amounts to three meals and a meeting can give it a lift.

"The gulf separating the government of Russia's official discourse and the United States' concept of what the relationship should be has gotten wider than it has been in a long, long time," said Stephen Sestanovich, an ambassador to former Soviet republics under President Clinton who now is at the Council on Foreign Relations.

For decades, relations between Washington and Moscow have been particularly defined by the personal chemistry between the people at the top, said Sarah Mendelson, Russia policy expert and senior fellow at the Center for Strategic and International Studies.

Think Reagan and Gorbachev or Clinton and Yeltsin.

The relationship between Bush and Putin started with a bang in June 2001 with the president's now-infamous assessment of Putin.

"I looked the man in the eye. I found him to be very straightforward and trustworthy," Bush said after that first meeting, in Slovenia. "I was able to get a sense of his soul: a man deeply committed to his country and the best interests of his country."

Even at the time, critics said Bush's unconditional praise -- intended by most accounts as a tactical attempt to connect with Putin and speak of hope as reality -- was nonetheless naive, given a crackdown on civil society groups in Russia that had begun and Moscow's brutal war in Chechnya.

The attacks of Sept. 11, 2001, came just three months after the Slovenia meeting. Putin offered bold and immediate terrorism-fighting support that endeared him to Bush. The next May, at a Moscow summit, the leaders signed a landmark nuclear arms reduction treaty and agreed to a broad cooperative agenda.

But problems hovered.

Bush's moves to expand missile defense, including withdrawing from the 1972 Anti-Ballistic Missile Treaty, rankled Russia. The Kremlin's politically charged campaign against the Yukos oil company and its leaders alarmed Washington.

The acrimonious debate leading up to the Iraq invasion in March 2003 cooled things considerably.

The two sides also sniped about interference in Ukraine's 2004 presidential election. Generally, the Kremlin chafed at what it saw as U.S. meddling in its sphere of influence, through NATO expansion and relations with former Soviet republics.

In 2005, at a meeting in Bratislava, Slovakia, U.S. concerns about democratic backsliding in Russia spilled into the open.

In recent months, a string of developments has caused a deeper slide, even amid greater cooperation against Iran's nuclear program and broader weapons proliferation.

Moscow's unrelentingly hostile response to Bush's plan to build a missile defense system in Europe, based in the Czech Republic and Poland, has included threatening to aim missiles at Europe and inflammatory rhetoric denouncing the United States' "hyper use of force" in the world.

Russia is blocking independence for Kosovo, favored by the U.S. Russia also is aiding separatists in Georgia and Moldova and has prevented peaceful demonstrations in Moscow. There are worries about Russia's manipulation of energy resources.

Putin, appealing to nationalist sentiments at home and eager to re-establish Russia's geopolitical stature, bristles at U.S. criticism of human rights in Russia. He says the U.S. missile defense system on Russia's doorstep, in former Soviet satellites, is a security threat.

Said Kremlin spokesman Dmitry Peskov: "There is a great need for extra attention, extra attention on the highest level."

The Kennebunkport meeting was suggested by Putin. Bush chose the setting, the oceanfront compound built by his great-grandfather over 100 years ago on a finger of rock jutting into the water.

"They are both now playing for history and legacy, and I really don't think that either of them want, as part of their legacy, a trashed U.S.-Russian relationship," said Andrew Kuchins, a Russia expert at the Center for Strategic and International Studies in Washington.

But neither side has shown any give on the issues most dividing them, such as missile defense or Kosovo.

"There really are no obvious candidates for a breakthrough issue that would impart a positive momentum to the broader relationship," said Steven Pifer, a deputy assistant secretary of state during Bush's first term.