On Jan. 22, 2025, U.S. Secretary of State Marco Rubio announced that the Trump administration was designating Ansar Allah, the name used by the Houthi Islamist terrorist movement, as a Foreign Terrorist Organization (FTO). Since 2023, in response to Israel’s invasion of Gaza, the Houthis had been conducting terrorist attacks from their stronghold in Yemen on global shipping in the Red Sea, through which an estimated 12 percent of all international trade passes. After Rubio’s announcement, the United States engaged in a campaign of airstrikes on Houthi positions in Yemen as part of Operation Rough Rider. While the airstrikes may temporarily degrade the capacity of the Houthis to engage in terrorism, it is also critical to consider the root factors that gave rise to the group and continue to sustain its terrorist activities, specifically the weakness of the Yemeni State.
In two recent studies, we examined the connection between weak States and resident terrorist organizations like the Houthis, using new data and research techniques. We found that terrorist groups residing in weak States are more resilient to countermeasures and possess longer lifespans. We also concluded that such organizations commit more domestic and transnational attacks, conduct more damaging attacks, and more frequently use disruptive tactics like kidnapping. In this piece, we explain our findings in more detail and briefly discuss current implications for global security. But first, we define a key concept.
What is State Weakness?
“Strong” States in the international system have several essential characteristics. They are able to police their domestic territories, enforce their rules and policies within their boundaries, and provide their citizens with basic physical and economic security. By contrast, “weak” States – sometimes also referred to as fragile States, failing States, or failed States – are unable to reliably do those things. They often contain “ungoverned” internal territories that they cannot effectively police or administer. Their citizens live in poor material conditions and are victimized by dangerous nonstate actors like rebel movements, criminal cartels, and terrorists. Yemen, where the Houthis are based, is widely considered to be a (severely) weak State, as are Afghanistan, Libya, Sudan, Syria, and Venezuela, home to other active resident terrorist groups.
Why Might Weak States Affect Terrorism?
Why might weak States function as incubators and sustainers of terrorism? Experts who hold this view offer several arguments. First, because they fail to adequately police their domestic territories, weak States provide a space for terrorist organizations to form, recruit members, plan attacks, train cadres, and launch terrorist attacks without interference from law enforcement. Such States also offer ample black market economy opportunities for terrorists to raise funds, acquire weapons, and secure other necessary resources. Corruption is usually rampant, limiting the ability of the government to respond to terrorist threats and the conditions that nurture terrorism. Because living conditions are poor within weak States, they teem with aggrieved, alienated, and resentful residents that are easy for terrorist groups to radicalize and recruit. In some extreme cases, such as al-Shabaab in Somalia, AQIM (al Qaeda in the Islamic Maghreb) in Mali or the Houthis in Yemen, terrorist organizations take advantage of official State weakness to effectively supplant the State in certain areas, further enhancing their abilities to recruit, radicalize, fundraise, and conduct attacks.
However, other experts argue that weak States are poor locations for terrorist organizations. Many weak States offer poor infrastructure and few local targeting opportunities, making it more difficult for terrorist groups to operate and gain attention through attacks. Terrorists are easily caught up in protracted local conflicts that threaten to distract them from their ideological missions. Terrorist organizations also face a larger array of hostile, predatory opponents in weak States such as rebel movements, criminal organizations, rogue government military and law enforcement agents, as well as rival terrorist actors. Foreign tourists, businesspeople, and aid workers are rarer in such States, thereby providing resident terrorist groups with few high-profile targets to attack or kidnap. Finally, there is less of an international taboo against conducting foreign military interventions in weak States, making resident terrorists more vulnerable to international policing efforts. All these considerations, in theory, may make it more costly and difficult for terrorist organizations to operate.
Our Findings
To answer the debate over whether weak States increase terrorism, we conducted two studies on a set of more than 600 terrorist organizations active in countries worldwide between 1970 and 2016. In the first study, we examined whether terrorist groups had a longer lifespan when operating in countries where the State collapsed – a severe manifestation of State weakness – and in countries where the state was unable to control a significant portion of its domestic territory. In the study, we considered (controlled for) other factors that we thought would also affect terrorist groups’ lifespan, such as the ideology and organizational capacity of the group and the demographics, poverty level, political system, regional location, and terrain of the country in which the group resided. In this first study, we derived some key findings. Terrorist groups live longer and have a lower annual propensity to end in countries experiencing state collapse. More specifically, we determined that for every 1 percent of domestic territory that a government lost control over, resident terrorist groups increased their lifespans by about 1.7 percent per year.
In the second study, we used the same set of more than 600 terrorist groups to examine how residence in a weak State affects attack behaviors. For this analysis, we assessed State weakness in several ways. To measure State administrative capacity and control over citizens, we utilized the government’s ability to collect income tax revenues and the share of the economically active workforce as a percentage of the total population. To quantify State policing capacity, we reused the measure of State control over domestic territory. Finally, we considered a host of other indicators of State weakness, such as those included in the Center for Systemic Peace’s State Fragility Index. This index combines States’ government effectiveness, perceived legitimacy, and ability to provide domestic security.
The second study’s analysis shows that all these measures of State weakness are associated with a noteworthy increase in resident terrorist organization attacks. Terrorist groups residing in States with reduced administrative capacity, impaired ability to control their populations and territory, and diminished government effectiveness, legitimacy, and security commit more domestic and transnational terrorist attacks. Furthermore, terrorists in such States more frequently engage in kidnappings, a form of terrorism that we argue is fostered in conditions where State’s territorial authority is particularly compromised.
As Weak States Proliferate, So Do Terrorists
Our research shows that weak States on the whole provide nurturing environments for terrorist organizations. State weakness boosts the organizational vitality of resident terrorist groups, enabling them to not only live longer but also expand their terrorist activities. Our studies also show that weak States enhance terrorist threats for both the host country’s citizens through domestic attacks and the wider international community through transnational attacks.
What our research suggests is that as long as Yemen remains a weak State, unable to police its own territory and unable to properly administer to and provide for the needs of its own citizens, the Houthis will remain a potent threat to domestic and international security. In addition to orchestrating Operational Rough Rider to militarily counter the Houthis, the Trump Administration also plans to cut the State Department’s annual budget by nearly 50 percent, eliminating budgeting for critical overseas staff, international organizations, and other programs that are devoted to stabilizing weak States. Some of the countries most affected by these cuts include Afghanistan, Somalia, and Sudan, three critically weak States that, like Yemen, shelter active resident international terrorist organizations. A world in which weak States proliferate and worsen is one in which terrorist threats like the Houthis will become more acute.
