All Policy Analysis by ماثيو ليفيت

Targeting Khorasan's leader is important, but what makes the group so frightening is its presence in Syria, where al-Qaeda explosives experts can mingle with radicalized foreign fighters carrying Western passports.

A newly created agency aimed at curbing the flow of money to terrorists will not amount to anything unless Qatar actually implements and enforces the relevant laws.

A quick guide to the finances of the Islamic State of Iraq and al-Sham (ISIS), the world's best-funded terrorist group.

By siding with the Assad regime and taking up arms against Sunni rebels, Hezbollah has placed itself at the epicenter of a sectarian conflict that has nothing to do with its purported raison d'etre of fighting Israel.

In addition to hitting ISIS in Iraq and Syria, the United States should target the Assad regime's military infrastructure to ensure that Damascus cannot take advantage of the situation.

Washington Institute research explains the complexities of the Islamic State in Iraq and al-Sham (ISIS).

A primer on how the group has achieved its dominant position in Lebanese politics, engaged in terrorist activity worldwide, and played a major role in the Syrian war.

BICOM senior research fellow Alan Johnson interviews Matthew Levitt about a new proposal for disarming Hamas to prevent future military clashes with Israel.

The jihadist elements in Gaza are far fewer in number than Hamas members, and they lack the group's deep social roots and capacity for control through governance.

The group remains as strong as ever on the continent.

Turkey-based Hamas member Salah al-Arouri is uniquely suited to overseeing the group's operations in the West Bank.

The United States and its allies beat al-Qaeda on the battlefield several years ago, but ISIS has financed a resurgence in Syria and Iraq that poses no less a threat to regional stability.

A discussion of whether and how the United States or other outside actors might intervene to check the jihadist group's advance.

Hezbollah's past operations in Iraq show that a limited number of experienced "consultants," working with Iran's Qods Force, could significantly increase the lethality of the local Shiite militias currently gearing up to counter the ISIS offensive.

Israeli authorities have been targeting the group's financial networks in Europe and elsewhere for some time.

Deborah Kalb interviews Dr. Levitt on Hezbollah's potential involvement in Iraq, its commitment to Iran, and other issues.