A profile of the international terrorist network that the United States has singled out as the most serious threat to U.S. security.

Western Europe's burgeoning Islamic population continues to spark concerns about Muslim assimilation and a cultural divide.

Ayman al-Zawahiri, now America's most wanted terrorist, took over as the head of al-Qaeda in June 2011 after the killing of erstwhile head Osama bin Laden.

The International Monetary Fund, both criticized and lauded for its efforts to promote financial stability, finds itself again in the forefront of global economic crisis management. This Backgrounder examines the Fund's history and role.

Global food prices are being driven up by a number of factors including bad weather, low stocks, and unstable commodities markets. Combating price volatility and protecting food security will take increased agriculture production and better food distribution, experts say.

The dispute between President Obama and Congress over the legality of the U.S. military intervention in Libya has spurred new debate on the power of presidents to make and prosecute wars.

Mideast upheaval was a top issue at the G8, which is winding down today in France, along with nuclear safety, leadership of the IMF, and aid to Africa. This Backgrounder profiles the eight participants and their priorities.

Foreign governments, non-state actors, and criminal networks are targeting the digital networks of the United States with increasing frequency and sophistication. U.S. cybersecurity has made progress, but relies heavily on the private sector to secure infrastructure critical to national security.

Though shifts in demand and reduced production by some major producers have influenced oil prices, investor behavior is also increasing market volatility.

Pakistan is bracing for more turbulence in the wake of Osama bin Laden's killing. This Backgrounder looks at how state support for Islamist militants has led to growing religious intolerance in society.

Pakistan's intelligence agency, the ISI, faces persistent accusations of links to terrorism, despite repeated denials.

The scramble for energy alternatives has brought new focus on nuclear power in the United States, but its revival faces political and practical obstacles.

Violent acts by homegrown militant extremists in the U.S. have declined, but "lone wolf" attacks are on the rise. The post-9/11 legal and political landscape poses new challenges to law enforcement authorities seeking to prevent such attacks.

The Gulf of Mexico oil spill spotlights the growth of deepwater drilling and the challenges of balancing strong environmental regulation with efforts to expand U.S. domestic oil production.

New screening measures at U.S. airports are being called overly intrusive by some passengers and civil rights groups. National security experts advise using a system that relies more on intelligence, behavioral profiling, and empowering passengers.

Experts say Islamic law, or sharia, holds wide appeal for Muslim populations in many countries and is beginning to spread via democratic means, but it is also being used as a tool of Islamic militancy and extremism.

A new arms control agreement with Russia has met political opposition in the U.S. Senate, and some analysts believe its fate is tied to the outcome of the 2010 midterm elections. This Backgrounder examines the Senate debate.

A proposed groundbreaking nuclear deal between the United States and India is raising questions and concern in both countries.

This series of Backgrounders examines foreign policy issues in light of the 2010 midterm elections.

The war in Afghanistan hasn't been a major campaign issue even as public support for it has waned. This Backgrounder examines political backing for the war.