In the past several weeks, ISIS poured out its violence on three of the group's main enemies across the globe. First, Russian authorities concluded that a terrorist attack brought down a civilian airliner in late October, likely an ISIS response to the country's recent major intervention in Syria. Then ISIS claimed responsibility for a major attack against a Hezbollah-controlled area in Lebanon, demonstrating strategic depth and capability against its regional rivals. One day later, it conducted a series of horrific coordinated attacks in Paris.
But ISIS's recent turn to international terrorism comes against a broader backdrop of stagnation and military losses in Iraq and Syria. In the past six months, the anti-ISIS coalition, the Iraqi government, and U.S.-backed Kurdish forces have enjoyed some significant successes against the group. Recent ground operations have expanded Kurdish control in northern Syria and in western Iraq. Furthermore, over a third of the group's leadership has been eliminated over the past year. ISIS's leader Abu Bakr al Baghdadi was injured in an airstrike and was reportedly incapacitated. His heir apparent was killed in a separate airstrike. Earlier this month, so-called “Jihadi John,” ISIS's British executioner, and ISIS's leader in Libya were both killed in U.S. airstrikes.
Despite these successes, the swath of territory ISIS controls in its self-proclaimed caliphate is more than sufficient to provide a sanctuary for terrorist attacks in the region and overseas. Moreover, ISIS's succession scheme and extensive bureaucracies limit the impact of the coalition killing or capturing its senior leaders.
The threat ISIS poses today is graver than ever for two reasons: its war chest and its ability to attract foreign recruits from around the globe are both at their peak. Redoubling international efforts to cut off ISIS from these two pillars of its war machine is necessary to sap the group's strength.
ISIS's finances are strong, despite a year of coalition airstrikes on its oil infrastructure. The group made $500 million in oil revenue over the past year, according to the ISIS finance ministry and U.S. Treasury officials. Even if recent coalition airstrikes on ISIS-controlled oil infrastructure and tanker trucks in Syria successfully cut off most of ISIS's oil revenue, the group's territorial control will still afford it access to other lucrative local revenue sources, including hundreds of millions of dollars from taxation, extortion and agriculture. These revenues, not to mention a “strategic reserve” of up to $2 billion, are more than enough for ISIS to cover the costs of its caliphate in the Middle East and to finance continued terrorist attacks in Europe and North America....
The remainder of this commentary is available on nationalinterest.org.
Benjamin Bahney is a member of the adjunct staff and Patrick B. Johnston is a political scientist and at the nonprofit, nonpartisan RAND Corporation.
This commentary originally appeared on The National Interest on December 4, 2015.