The European Union won the Nobel Peace Prize on Friday, a choice that celebrates Europe’s post-World War II economic and political integration but comes as the 27-nation body confronts widespread criticism over its handling of a massive debt crisis that has become the biggest challenge of its existence.

The award honored the struggle in Europe to not only hold the union together in the wake of the debt crisis, but also to further its goal of deeper integration. Yet the decision to pay tribute to the E.U. now fed into a growing chorus of critics who argue that the Norwegian Nobel Committee has strayed from the award’s original ideals and into the realm of political theater, with objectors putting this year’s choice in the same category as the selection of President Obama in 2009, just months after he took office.

The decision, announced to audible gasps from a roomful of journalists in Oslo, came amid the widespread international perception that the E.U. has wreaked havoc in global financial markets by being bureaucratic and plodding in managing the crisis. It has also been accused of foisting onto its heavily indebted members a crushing austerity that has crippled domestic economies and sparked unrest in Greece, Spain and other nations.

“Twenty years ago, this prize would have been sycophantic, but maybe more justified. Today, it is downright out of touch,” said Martin Callanan, a Conservative British politician and chairman of the European Conservatives and Reformists group in the European Parliament. “The E.U.’s policies have exacerbated the fallout of the financial crisis and led to social unrest that we haven’t seen for a generation.”

By selecting the E.U., the Nobel Committee, however, appeared to be sending a message that in its darkest hour in decades, Europe should take stock in a major achievement: safeguarding peace and security and forging a common future for a continent saddled with a bloody history of conflict.

“The dreadful suffering in World War II demonstrated the need for a new Europe,” Thorbjoern Jagland, the Nobel Committee chairman, said in Oslo. “Over a 70-year period, Germany and France had fought three wars. Today, war between Germany and France is unthinkable. This shows how, through well-aimed efforts and by building up mutual confidence, historical enemies can become close partners.”

Jagland seemed to recognize the complication of selecting such a vast body for the prize: “This is a prize to the European Union. They have to decide what leader will come and receive the medal.” Nor was it clear what would happen to the estimated $1.5 million award.

Jose Manuel Barroso, president of the European Commission, the executive branch of the European Union, said the award shows that “even in tense, difficult times, the European Union remains an inspiration for countries and people all over the world.”

“This is indeed a great honor for the 500 million citizens of Europe,” Barroso said.

But if the union has instilled democracy and peace in Europe, it has also sowed fresh resentment in recent years. As borders have been erased around the region and trade has flowed freely, anxiety has grown in some countries over unfettered immigration as well as the economic dominance of the region by the E.U.’s core nations, Germany and France.

Nationalist parties are on the rise in Finland, France, Greece and Italy. Once again the economic powerhouse of Europe, Germany has been criticized for being reluctant to extend its largess to threatened European countries, including Greece and Spain.

The award also comes amid a widening gulf between the 17 E.U. nations that share the euro and the 10 nations still outside the common currency, with talk growing of a two-tiered body in which some nations would band more closely together while others would drift apart.

Anti-E.U. sentiment is on the rise in nations such as Britain, which has jealously guarded the British pound and where pressure is building for the Conservative-led government of Prime Minister David Cameron to hold a national referendum on whether to exit the union.

‘The award has been depersonalized’

The move to award the prize to a vast and varied organization follows a pattern in recent years of the Nobel Committee thinking outside the box — the International Atomic Energy Agency won in 2005; and the Intergovernmental Panel on Climate Change shared the honor with Al Gore in 2007. This year’s choice also amounted to a controversial pick for the Norway-based Nobel Committee, given that voters in that country have twice rejected membership in the E.U.

Critics of the decision to bestow the prize on the European Union noted that it has not been alone in heading off conflicts on the continent. As recently as the 1990s, it required the aid of the United States to settle the Balkans dispute on its own frontier. Some also chastised the committee for selecting an impersonal body.

“It’s just laughable,” Svetlana Gannushkina, a longtime Russian human rights activist whom Norwegian parliamentarians said they had nominated for the award, told Interfax. “The award has been depersonalized to such an extent. . . . The Nobel Committee could have defended the principles of peace and democracy if it had awarded the prize to those who have worked in this sphere for many years and now need support.”

In Germany, where opinion polls show that a majority of residents are still committed to European unity even as they tire of supporting their struggling neighbors, news of the prize was greeted with wide appreciation. Even the Web site of the Bild tabloid — normally a haven for militantly anti-euro headlines — proudly proclaimed the news, with the E.U.’s blue-and-yellow logo displayed in a lineup of past winners including Martin Luther King Jr. and Mother Teresa.

“I often say that the euro is more than a currency,” German Chancellor Angela Merkel said in a statement Friday. “As we work to strengthen the euro in these weeks and months, we should not forget this.”

French President Francois Hollande hailed the award as an “immense honor” that “commits us all to continue toward a Europe more united, more just, stronger and more capable of peacemaking.” But Marine Le Pen, who leads France’s extreme nationalist National Front party, said that honoring the European Union “demonstrates great cynicism toward the millions of Europeans who are suffering mortally” because of the debt crisis.

Commonality and support

The European Union was born from the ashes of World War II, with leaders seeking to bind their countries so tightly together that they would never again face each other in war.

In 1950, France and Germany launched discussions on how to commonly run their coal and steel industries, and other countries soon joined in the effort. By 1957, the agreements had evolved into a common market, with few trade barriers among the Western European countries that joined. In 1993, the market became the European Union; six years later, the common euro currency was introduced.

But many leaders still hold firm to the idea that common solidarity in the name of peace is the overarching goal. In 2004, many former Eastern Bloc countries gained entrance. Now, once-warring Balkan countries are slowly making their way into the union. Croatia plans to join next year.

For the new countries, membership confers status, economic support and a path toward euro membership. Smaller nations still feel that the benefits of the common currency outweigh the drawbacks. Those that were once under the thumb of the Soviet Union appreciate having a backer against modern-day Russia, of which many are still suspicious.

“Deeply touched honored that the E.U. has won the Nobel Peace Prize,” the head of the European Parliament, German Socialist Martin Schulz, posted on Twitter moments after the award was announced. “Reconciliation is what the E.U. is about. It can serve as inspiration.”

Birnbaum reported from Berlin. Edward Cody in Paris and Kathy Lally in Moscow contributed to this report.