The Islamic State opened up a new front when it downed a Russian passenger plane in October over Egypt’s Sinai Peninsula. U.S. and allied attention understandably focuses on the terrorism threat posed by the Islamic State (also known as ISIS, ISIL, or Daesh) to their own homelands or on the carnage in Syria, now estimated to have consumed almost 500,000 lives. But the Russian plane crash was a different beast: the Islamic State itself did not do the attack, but rather another jihadist group, which had pledged loyalty to Islamic State leader Abu Bakr al-Baghdadi.

Groups pledging loyalty to the Islamic State can be found in parts of Afghanistan, Algeria, the Caucasus, Egypt, Libya, Nigeria, Pakistan, Saudi Arabia, Somalia, and Yemen (here’s a cool map). Other countries – including France, Belgium, and Tunisia, to name a few – have seen terrorists operating in the Islamic State’s name. So far, the most worrisome of these offshoots are those in Sinai and Libya. Sinai is worrisome because the Russian plane attack suggests it is looking for targets outside its immediate theater of conflict, and the Libyan province appears dangerous because of its size and close relations to the core organization in Iraq and Syria.

The Islamic State calls these groups wilayat, or provinces. (The term is borrowed from the 7th century Muslim conquest, when the armies of Islam burst out of the Arabian Peninsula – a period considered a golden age by many Muslims – and established regional governors who ruled over many areas they conquered in the name of the caliph; the Ottoman empire, when the caliphate was last active, also used the term.) If, as recent events suggest, the Islamic State’s provinces have begun closely aligning their actions with the group’s core leadership in Iraq and Syria, then the geographic scope of the dangers posed by the Islamic State will have expanded vastly.

We’ve seen this movie before. After 9/11, Al Qaeda established affiliates throughout the Muslim world. Some, particularly Al Qaeda in the Arabian Peninsula (AQAP), emerged as deadly dangers. Indeed, the Islamic State itself also began as an Al Qaeda franchise.

If, as recent events suggest, the Islamic State’s provinces have begun closely aligning their actions with the group’s core leadership in Iraq and Syria, then the geographic scope of the dangers posed by the Islamic State will have expanded vastly.

As I argue in the latest Foreign Affairs, the provinces pose a threat to Western interests in the Middle East and perhaps to Western homelands: they enable the Islamic State to expand its reach and make local groups more deadly in their regional conflicts. Hotbeds of jihad that have not yet exported terrorism to the West may do so in the future if the Islamic State central gains more control over these regional groups.

Accepting the Islamic State label can often lead local groups to shift tactics and ideology. In addition to fighting local government forces and rival groups as they did before, many provinces begin making sectarian attacks and targeting Westerners in the region. They often behead their victims and carefully choreograph and videotape the executions for broad dissemination. When possible, as in parts of Libya, provinces also govern as the Islamic State does in Iraq and Syria, complete with police, courts, and taxes. So far, however, no Islamic State province has attacked targets outside its region of operations.

Local groups, for their part, find the Islamic State attractive in part because they admire its emphasis on sectarianism and apocalypticism. Some groups seek financial or technical aid. Finally, taking on the Islamic State brand permits aspiring local commanders to enhance their credentials with claims of doctrinal purity – masking their power grab – to quell any potential backlash from their followers.

As the Islamic State grows beyond Iraq and Syria, it spreads its harsh brand of religious intolerance, and attacks on Shiites and other religious minorities are spreading. The Middle East’s already horrific humanitarian situation will get worse, and tactics like beheading and sexual slavery will grow more common. The violence and sectarianism also threaten the legitimacy and stability of U.S. allies in the Middle East. From the West’s perspective, however, the bigger concern is that as the Islamic State expands, it will develop new havens and staging grounds to use for international terrorist attacks.

As I argue in the latest Foreign Affairs, the provinces pose a threat to Western interests in the Middle East and perhaps to Western homelands: they enable the Islamic State to expand its reach and make local groups more deadly in their regional conflicts.

Provinces, however, also pose their share of problems for the jihadist cause. The infighting that leads splitters to embrace the Islamic State has led jihadists to turn their guns on each other, weakening them against other enemies. Nor are the provinces likely to be obedient servants, particularly if the core cannot keep the money and volunteers coming. They have their own command structure and interests, and these do not always match those of the Islamic State core. For example, Western officials told the New York Times that when the leaders of its Sinai province decided to bomb the Russian plane, they did so without consulting the Islamic State’s leaders. And the move provoked Russia, which until then had limited its airstrikes in Syria to attacks on the moderate opposition, to launch cruise missiles on the Islamic State’s forces and infrastructure in Deir ez-Zour and Raqqa, among other targets (though most Russian strikes still hit the moderate Syrian opposition). Local provinces, for their part, may lose local support if they respond to their masters in Iraq and Syria rather than the wishes of the local people.

Islamic State provinces are slowly entering the policy debate. The United States is considering greater intervention in Libya to push back the Islamic State province there. The Pentagon has begun to take the danger more seriously and is considering building additional military bases in Africa, Asia, and the Middle East, in part because it wants more flexibility to meet this threat.

But the United States and its allies must go further and develop a comprehensive strategy to weaken the Islamic State’s various provinces. They should start by taking advantage of the tensions that will inevitably arise between the Islamic State leadership in Syria and Iraq and its more remote branches. Al Qaeda’s affiliates eventually became a burden for the group’s core — demanding resources, ignoring its directives, and tarring its name by conducting unpopular attacks.

Any strategy aimed at weakening the provinces and exploiting these problems must include two parts: cutting the link connecting the Islamic State core to its affiliates, while also attempting to contain, weaken, and defeat the provinces themselves. To that end, the United States and its allies should target provincial command-and-control centers and locals who have personal relationships with top Islamic State leaders in Syria and Iraq. Deprived of instruction from headquarters, the provinces will be forced to go their own way, which could create a world of new problems for the Islamic State’s core and deprive them of local allies.