With oil supplies tight, regions most vulnerable to oil supply disruptions present a significant economic concern, particularly threats to the Strait of Hormuz and unrest in Nigeria, explains this Backgrounder.

Iran's record on human rights is markedly deteriorating amid a regime power struggle and growing international pressure linked to its nuclear program. Analysts say the international community must intensify the spotlight on Iran's rights abuses.

The U.S. government designates Iran as the "most active state sponsor of terrorism," which feeds concerns about Iran's growing nuclear program.

Iran's nuclear program is believed to have steadily progressed, despite sharply increased concerns over its intentions and sanctions over its lack of transparency.

Despite concerns over Iran's nuclear program, the Obama administration has assessed that Tehran is years from a developing a long-range missile capable of delivering a nuclear weapon. But past Iranian secrecy and testing bombast have led some experts to remain skeptical of Tehran's capabilities and ambitions.

In the aftermath of the June 2009 presidential election, Iran's Revolutionary Guard Corps has become major to the regime's power projection. Some analysts have seen the guard's hand in a creeping militarization of Iran's domestic policy.

The crisis following Iran's presidential vote cast a new light on the country's hotly contested media space. A crackdown has limited independent reporting but other sources remain as channels for dissent.

Iran's Supreme Leader remains the regime's ultimate authority but controversy surrounding the country's June 12 presidential election has raised new questions about the role and power of the head of state.

U.S. and Western military officials are calling on Iran to help stabilize Afghanistan, but historic tensions and allegations of arming militants raise doubts about Tehran's intent.

Religion's place in the Iranian political system has long been debated among scholars, but a president who blurs the line has refocused attention on the topic

Whether to engage heads of rogue states, a perennial foreign policy dilemma, has emerged in the 2008 U.S. presidential campaign.

Examining the life and tactics of Imad Fayez Mugniyah, the Hezbollah military mastermind killed in Damascus on February 13, 2008. Before 9/11, Mugniyah was said to be responsible for the deaths of more Americans than any other terrorist.

Iran’s alleged meddling in Iraq and Afghanistan and its defiance of orders to halt uranium enrichment have drawn sharp criticism from the west. Amid the rhetoric some analysts and policy makers continue to question the quality and credibility of Washington’s intelligence on Tehran, while a new National Intelligence Estimate adds to the uncertainty.

The arrests of four Iranian-Americans have created a chill among those in Iran working to open up civil society and led to disagreements over U.S. support for those efforts.

Since cutting ties in 1979, U.S.-Iran dialogue has been sparse and largely fruitless.

Backgrounder: Economists say Iran's mismanaged energy sector and falling oil prices could have consequences for its economy.

Iran's influence in Iraq is the subject of enormous speculation. The United States is taking steps to counter that influence.

Backgrounder: The financial levers Washington is applying to bring about a suspension of Iran’s nuclear program.

A pair of important elections in Iran may indicate which direction the public mood is swinging ahead of parliamentary polls next year.

Iran is a predominantly Shiite Muslim state but contains sizeable ethnic and religious minorities that influence Iran’s foreign and regional policy.