* Obama shifts from domestic affairs, makes debut abroad
* Break from Bush style, policies to set positive tone
* Obama faces resistance on economic ideas, Afghanistan
(Updates with Obama arrival in Britain)
By Caren Bohan
LONDON, March 31 (Reuters) - President Barack Obama arrived in Europe on Tuesday with a hefty agenda for tackling the economic crisis and seeking support for his new Afghanistan strategy on a trip that will test his global leadership.
Flying into Stansted Airport near London to begin his first major foreign trip since taking office in January, Obama will quickly shift focus to international economics and diplomacy after a heavy emphasis on domestic issues.
He will attend a summit of the Group of 20 major economies this week in London, then go to a NATO summit on the French-German border before stopping in the Czech Republic and Turkey. His schedule includes meetings on the sidelines of the G20 with the leaders of Russia, China and other nations.
The Democratic U.S. president hopes to capitalize on a reservoir of goodwill because of the change in policies and style from his Republican predecessor, George W. Bush, who was unpopular abroad.
Analysts said enthusiasm for Obama among the public in Europe will make for a positive tone in his meetings with allies such as British Prime Minister Gordon Brown, French President Nicolas Sarkozy and German Chancellor Angela Merkel.
But the warm personal reception Obama will receive might not ease the way for his aims of prodding European allies to spend more to rescue the global economy and offer more troops and resources for the Afghanistan war.
"He's obviously got a lot of charisma and it's his first big meeting. And I think people tend to be very polite in these situations but there could also be a level of awkwardness there," said Simon Johnson, a former IMF chief economist who is now a professor at the Massachusetts Institute of Technology.
One theme at the economic summit will be a view in many countries that the United States bears much of the blame for the global financial meltdown because of its lax financial regulation and the debt-fueled U.S. housing bubble.
Obama has sought to distance himself from the Bush-era regulatory policy. He will take to the G20 an array of proposals to bring new oversight to hedge funds and other players and to give the U.S. government greater powers to deal with troubled financial firms deemed "too big to fail."
"It should be the case that he can walk in there and say, none of this was my fault and I'm cleaning up as fast as I can," Johnson said.
But the cloud of blame hanging over the United States is one reason Obama faces reluctance among Europeans to follow his lead and pursue big fiscal economic stimulus plans such as his $787 billion recovery package, Johnson said.
White House aides have sought to manage expectations before the G20 summit, telling reporters Washington is not necessarily asking countries to spend more right away.
P.J. Crowley, a former official in President Bill Clinton's White House, agreed that Obama still will have something of a honeymoon period with his European counterparts. But, similar to the G20 summit, there may be resistance at the NATO gathering to his pleas for support for Afghanistan.
"Because he is popular and he isn't George W. Bush, European leaders are going to have an interest in this being seen as a successful first encounter," said Crowley, who is now with the Center for American Progress think tank.
The improvement in tone "doesn't necessarily solve the problem that Afghanistan is a very complex situation" and persuading European allies to devote more resources to the war there at a time of economic crisis will be tough, Crowley said.
At the NATO summit in Strasbourg, France, the leaders will celebrate the 60th anniversary of the transatlantic alliance. In a move symbolizing closer Franco-American ties, France is rejoining NATO's military command after decades of self-imposed exile.
Obama will use the NATO summit to further explain a strategy he unveiled this week for Afghanistan that puts a strong focus as well on Pakistan. It sets as the main goal the defeat of al Qaeda and Taliban militants.
Obama will send 4,000 U.S. troops to help train the Afghan army and will add more civilian personnel, but he also wants NATO partners to pitch in more resources. (Reporting by Caren Bohan; Editing by Chris Wilson)