MCLEAN, Va. — The world of 2020 is likely to be one in which Asia is the main engine of the global economy, India and China are major powers and al-Qaida-inspired Islamist movements have spread to Muslim communities outside the Middle East, a new U.S. intelligence report said yesterday.

The United States will remain "the single most important country across all dimensions of power," but wield less authority than it does now because of the greater influence of India, China and possibly other nations such as Brazil and Indonesia.

"Although the challenges ahead will be daunting, the United States will retain enormous advantages, playing a pivotal role across the broad range of issues — economic, technological, political and military — that no other state will match by 2020," said the report, "Mapping the Global Future."

It was the third in a series of unclassified forecasts of global trends published by the National Intelligence Council, a group of senior intelligence analysts who report to CIA Director Porter Goss but technically aren't part of the spy agency. The earlier reports were for 2010 and 2015.

Their forecasts for 2020 were based on consultations with more than 1,000 nongovernment experts at 30 conferences on five continents over the past year.

"Mindful that there are many possible 'futures,' our report offers a range of possibilities and potential discontinuities, as a way of opening our minds to developments we might otherwise miss," said National Intelligence Council Chairman Robert Hutchings, who released the report.

Barring catastrophic war or a worldwide depression, the global economy is expected to be 80 percent larger in 2020 than it was in 2000, with average per-capita income 50 percent higher.

Yet while more people will prosper, there will still be many places that are poor and unstable, particularly in the Middle East, sub-Saharan Africa and parts of Latin America, the report said.

China and India are likely to be among the leading beneficiaries, in part because of their low-cost labor and high technology capabilities. Many of their people, however, will remain poor.

By 2020, China's gross domestic product, the total value of goods and services, will be greater than that of any Western country except the United States, and India's GDP will have overtaken or will be about to overtake European economies. Led by China and India, Asia "looks set to displace Western countries as the focus of international economic dynamism — provided Asia's rapid economic growth continues," it said.

The report said the likelihood of a dispute between major powers escalating into all-out war "is lower than at any time in the past century, unlike during previous centuries when local conflicts sparked world wars."

Still, a miscalculation could trigger major wars, such as a conflict between nuclear rivals India and Pakistan.

Smaller wars are still likely.

"Weak governments, lagging economies, religious extremism" and populations with large numbers of disadvantaged young people "will align to create the perfect storm for internal conflict in certain regions," the report warned.

The threat of terrorism will remain high.

"Our greatest concern is that terrorists might acquire biological agents, or less likely, a nuclear device, either of which could cause mass casualties," the report said. Terrorists will continue to rely primarily on conventional weapons, it said.

"There is a substantial risk that broad Islamic extremist movements akin to al-Qaida will merge with local separatist movements," it continued.

The report presented one scenario, dubbed "The New Caliphate," in which an obscure Islamic cleric emerges to lead a worldwide Islamic movement.

Mapping the Global Future

The report can be read online www.cia.gov/nic/NIC_2020_project.html