But Bush is also bookending his stay at the summit in Germany with Putin and the leaders of six other industrialized nations with calls on the Czech Republic and Poland, former Soviet satellites where Bush wants to base major parts of the new shield.
It could hardly be seen as anything less than a poke in the eye to Putin.
"This is a distinctive message that is as easily understandable in Russian as it is in English," said Simon Serfaty, a senior adviser to the Europe program at the Center for Strategic and International Studies. "The message is that we're going to do, and your concerns about the deployment of some marginal capabilities designed for defense purposes in Central Europe are not going to impress me."
Putin, speaking to foreign reporters before he travels to Germany for the summit, warned that Moscow could take "retaliatory steps" if Washington goes forward with the missile plan, including possibly aiming nuclear weapons at targets in Europe.
Bush was due to arrive later Monday in Prague at the start of an eight-day, six-country European jaunt. Besides the Czech Republic, Germany and Poland, Bush also has Italy, Albania and Bulgaria on his travel itinerary. He has meetings planned with at least 15 foreign leaders, plus Pope Benedict XVI, and his schedule is not final yet.
But the spat with Putin is likely to be the dominant theme.
U.S. officials have insisted - publicly and to Putin personally - that the system planned for Eastern Europe is meant to protect NATO allies against a missile launch from Iran, which the West suspects of trying to develop nuclear weapons. Moscow is not buying it, insisting the system must be aimed at Russia and accusing Washington of touching off a new arms race.
Saying it is now forced to strengthen its military potential, Russia test-fired new missiles and declared a moratorium on observing its obligations under a key Soviet-era arms control treaty. Putin also has unleashed a volley of incendiary remarks Washington's way, criticizing "imperialism" in global affairs, saying the shield would turn Europe into a "powder keg" and accusing the U.S. of "an almost uncontained hyper use of force."
The missile defense flare-up came on top of Washington worries about backsliding on democracy under Putin's leadership - even as the U.S. courts Russia's assistance in curtailing Iran's and North Korea's nuclear programs. Putin, meanwhile, is increasingly riled over what he views as U.S. meddling in his backyard.
To settle things down, Bush has invited the Russian leader for an unprecedented stay at his family's summer compound on the Maine coast in July. But he also is hosting Estonia's president at the White House the week before. Like the Czech and Polish stops, this meeting will not please the Russians, angry with Estonia for moving a memorial to Soviet soldiers killed during World War II.
The overarching message from the Bush administration has been: calm down.
"The Cold War is over," Bush told foreign reporters before the trip. "We're now into the 21st century." He called the Washington-Moscow relationship "complex" - a term previously used mostly to describe the U.S.'s tricky ties with China.
This sort of strategic travel-planning isn't new for Bush.
The president agreed to attend Putin's Red Square celebration in May 2005 of the 60th anniversary of WWII's end. But he started that trip in Latvia and ended it in Georgia, both ex-Soviet republics that the president used as backdrops for rhetoric on the power of democracy.
Later that year, Bush made a state visit to communist China. But first he delivered a pointed speech in Japan that amounted to a lecture for Beijing to increase political and economic freedoms. And he flew directly from China to Mongolia, the first Asian nation to discard communism in favor of democracy.
Other presidents have done it, too.
When President Richard Nixon traveled to Moscow in 1972, for instance, he made counterweight stops in Poland and Iran.
"It has some benefit in trying to demonstrate to people who might be critical of policies that there's a broader set of initiatives being pursued, often to critics back home," said Stephen Sestanovich, senior fellow for Russian studies at the Council on Foreign Relations.
Lavishing attention on smaller countries facing pressure from their more powerful neighbors can back up Bush's promise to predicate U.S. relations with all nations on their treatment of their citizens, and to advance democracy in every corner of the globe. At the Radio Free Europe building in Prague on Tuesday, the president is delivering a speech on the importance of supporting democratic aspirations and meeting with current and former dissidents from around the world.
"When he goes to NATO or he visits a major industrialized country, he goes out of his way to got to Baltics or to some part of the former Soviet Union to sort of send a message that we're behind this agenda," said Charles Kupchan, director of Europe studies for the Council on Foreign Relations. "I think it really does make a difference."
For Bush, unpopular at home and in much of the world, it also offers photographic proof he still is revered in some places.
In the impoverished, struggling young democracy of Georgia, for instance, the main road from Tblisi's downtown to the airport has been called George W. Bush Avenue since his visit.
"There are countries that tire of having Air Force One touch down," Sestanovich said. "But very small countries that rarely get the treatment can respond in very positive ways. And presidents who aren't used to that kind of adulation at home anymore sometimes find it invigorating."