FACTBOX: Iran, North Korea, al Qaeda top threats in U.S. review

WASHINGTON (Reuters) - Iran's nuclear program, North Korea's "erratic behavior" and insurgencies fueled by militant groups like al Qaeda top the list of security challenges facing the United States, according to a U.S. intelligence assessment released on Tuesday.

The 2009 national intelligence strategy, setting out priorities for the nation's 16 intelligence agencies for the next four years, listed military and economic challenges from long-time foes, as well as countries like China and Russia:

IRAN

"Iran poses an array of challenges to U.S. security objectives in the Middle East and beyond because of its nuclear and missile programs, support of terrorism, and provision of lethal aid to U.S. and Coalition adversaries."

NORTH KOREA

"North Korea continues to threaten peace and security in East Asia because of its sustained pursuit of nuclear and ballistic missile capabilities, its transfer of these capabilities to third parties, its erratic behavior, and its large conventional military capability."

CHINA

"China shares many interests with the United States, but its increasing natural resource-focused diplomacy and military modernization are among the factors making it a complex global challenge."

RUSSIA

"Russia is a U.S. partner in important initiatives such as securing fissile material and combating nuclear terrorism, but it may continue to seek avenues for reasserting power and influence in ways that complicate U.S. interests."

'EXTREMIST' GROUPS

"Violent extremist groups are planning to use terrorism -- including the possible use of nuclear weapons or devices if they can acquire them -- to attack the United States. Working in a number of regions, these groups aim to derail the rule of law, erode societal order, attack U.S. strategic partners, and otherwise challenge U.S. interests worldwide."

INSURGENCIES

"Insurgents are attempting to destabilize vulnerable states in regions of strategic interest to the United States."

ECONOMIC TURMOIL

"The global economic crisis could accelerate and weaken U.S. security by fueling political turbulence. In some developing economies, a sustained slowdown could induce social and political instability, while in others it could erode support for market-oriented liberal democracy and create openings for authoritarianism."

'FAILED' STATES

"Failed states and ungoverned spaces offer terrorist and criminal organizations safe haven and possible access to weapons of mass destruction and may cause or exacerbate starvation, genocide, and environmental degradation."

CLIMATE CHANGE

"Climate change and energy competition may produce second-order effects for national security as states anticipate the effects of global warming (e.g., by contesting water resources in regions with limited potable sources) and seek to secure new energy sources, transport routes, and territorial claims."

TECHNOLOGICAL CHANGE

"Rapid technological change and dissemination of information continue to alter social, economic, and political forces, providing new means for our adversaries and competitors to challenge us, while also providing the United States with new opportunities to preserve or gain competitive advantages."

PANDEMIC

"As the 2009 H1N1 influenza outbreak vividly illustrates, the risk of pandemic disease presents a persistent challenge to global health, commerce, and economic well-being."

(Reporting by Adam Entous; Editing by Eric Beech)