WASHINGTON (AP) — Weaving together strands of pomp, policy and summitry, President Barack Obama’s weeklong European tour is all about tending to old friends in the Western alliance and securing their help with daunting challenges, from the political upheaval in the Mideast and North Africa to the protracted war in Afghanistan.

Obama’s eighth trip to Europe as president, with a quick-moving itinerary that dips into four countries in six days, unfolds against the backdrop of the NATO-led bombing campaign in Libya and stubborn economic weakness on both sides of the Atlantic.

A priority for the president and his allies will be to more clearly define the West’s role in promoting stability and democracy in the Arab world without being overly meddlesome and within tight financial limitations.

Obama, who departs late Sunday, will visit Ireland, England, France and Poland. Each is weathering an economic downturn that has forced European nations to adopt strict austerity measures. The U.S. has pushed its national debt to the limit, and Obama and congressional Republicans are in contentious talks about how steeply to cut spending.

But never mind all that, at least for a moment.

A highlight of Obama’s opening stop in Ireland will be a feel-good pilgrimage to the hamlet of Moneygall, where America’s first black president will explore his Irish — yes, Irish — roots, and most likely raise a pint.

It turns out that Falmouth Kearney, who immigrated to the United States in 1850 at the age of 19, is the great great great grandfather of Obama on his white, Kansas-born mother’s side. Obama, whose father was born in Kenya, will connect in Moneygall with distant relatives from the Irish branch of his family tree.

Michael Collins, the Irish ambassador to the United States, says the president’s visit will be “a golden moment” for a country that’s been on the economic ropes after its boom time. The visit is sure to play well at home for Obama — make that O’bama — as he heads into re-election season after being pushed to great lengths simply to prove he was born on U.S. soil.

After his day in Ireland, Obama spends two in England, where he and first lady Michelle Obama will be treated to all the pomp and pageantry that the monarchy can muster for the president’s first European state visit. The Obamas even get a Buckingham Palace sleepover.

Though the United States and Britain remain the closest of allies, the relationship has been strained by recent events, including last year’s oil spill in the Gulf of Mexico triggered by the explosion of an oil rig owned by British-based BP. Britain’s unilateral announcement of a timetable for withdrawal of its 10,000 troops from Afghanistan also rankled the United States.

Heather Conley, director of the Europe program at the private Center for Strategic and International Studies, said Obama’s stop in Britain could help “put the ‘special’ back into the U.S.-U.K. special relationship.”

Obama on Wednesday will become the first American president to speak to members of Parliament from the historic Palace of Westminster. European leaders are eager to see how president frames the U.S.-European partnership at a time when Obama has prodded Western allies to shoulder greater responsibility in areas such as Afghanistan and Libya. A NATO-led mission is working to protect civilians and assist the rebel fighters trying to oust Libyan leader Moammar Gadhafi.

Former Liberal Democrat leader Menzies Campbell, a member of the House of Commons foreign affairs committee, said British politicians would be listening keenly to what Obama had to say about Afghanistan when he addresses both houses of Parliament on Wednesday.

“The death of Osama bin Laden can only encourage those with the ear of the president to proceed more quickly with the draw-down of American forces in Afghanistan,” Campbell said. “MPs and peers alike will be listening closely to what he says about America’s intentions for Afghanistan.”

In private, Obama and British Prime Minister David Cameron will plunge into the details of a host of international challenges on which the U.S. and Britain have worked together: Afghanistan, Libya, counterterrorism, the global economy and more.

Both leaders then scoot to a French summit of the Group of Eight industrialized nations, where the president hopes to build on momentum from his speech days ago about how best to promote stability and democracy in the Middle East. Obama has called on the World Bank and International Monetary Fund to present the G-8 with an ambitious plan to help Egypt and Tunisia, in particular, recover from the disruptions caused by their democratic revolutions and prepare for elections later this year.

The U.S. and its allies don’t want those elections to occur against a backdrop of economic chaos that could increase support for extremists. But there’s no expectation of a big aid measure emerging from the G-8. Rather, the countries in the region will present their plans for democratization and stabilizing their economies, and the G-8 will consider ways to help.

Although not on the official agenda, the G-8 leaders are sure to be talking about future leadership of the IMF now that former chief Dominique Strauss-Kahn has resigned after being arrested on attempted rape charges in New York. European leaders are anxious to put another European in that position while emerging economies would like to see a process that is open to someone from the developing world. U.S. officials have said they favor an open process, without being more specific.

Obama’s visit to Europe comes a little more than a month before the U.S. is scheduled to start its gradual troop withdrawal in Afghanistan. The president has said the initial drawdown will be significant, but it’s unclear how many specific answers he’ll have for European leaders. Britain and France, in particular, are looking for details on the U.S. withdrawal timetable for signs of how NATO will move from combat missions to a training role by the end of 2014.

The Afghan mission is deeply unpopular in many European countries, and political pressure has led some leaders to set timetables for their withdrawal. The British are planning to draw down 400 of their nearly 10,000 troops this year, with all British troops out by the end of 2014. France, which has 4,000 troops in Afghanistan, has said it is considering speeding up its withdrawal now that al-Qaida leader Osama bin Laden is dead.

During his two-day stay in Deauville, France, Obama will take time for one-on-one meetings on the side of the G-8 with several world leaders, including Russian President Dmitry Medvedev and Japanese Prime Minister Naoto Kan.

The U.S.-Russia relationship, though much improved since the Bush administration, remains complex.

Medvedev has spoken out strongly in recent weeks against U.S. plans to plant missile interceptors in Romania as part of a U.S. shield over Europe, saying that could threaten Russia. He’s warned that Washington’s failure to cooperate with Russia on the missile shield could lead to a new arms race, and also threatened to pull out of the New START nuclear treaty with the U.S. if Russia feels at risk.

Obama’s meeting with Kan would be his first with the Japanese prime minister since the March tsunami and earthquake that triggered a nuclear crisis in Japan. The U.S. has sent military and humanitarian assistance to Japan, as well as nuclear experts, to help the country recover from the disaster.

Obama’s visit to Poland is emblematic of a growing front in the administration’s engagement in Europe, as the U.S. expands its economic and security relationship with Central European nations.

Robert Kupiecki, Poland’s ambassador to the United States, says Central Europe’s experiences in moving toward democracy offer many lessons that are “directly applicable” in the Middle East and North Africa, and that Poles and others in the region are anxious to help the democratic movement spread. Lech Walesa, the former Polish president who founded the Solidarity freedom movement, has visited Tunisia, and Walesa will meet with Obama in Poland to talk about the experience.

Obama can point to Poland, with its stable government and growing economy, as a benefactor of democracy’s virtues.