Terrorism in West Africa is evolving into a more regional phenomenon. In order to hold back wider destabilization, international partners would be wise to emphasize regional cooperation in response.

Take the latest attacks. In late November 2015, militants used grenades and assault rifles to take over a popular hotel in Bamako, Mali, holding more than 100 hostages for several hours and killing 19 civilians. A similar incident occurred in neighboring Burkina Faso in January. The 12-hour occupation of a Ouagadougou hotel cafe favored by expats left 30 dead and 56 more injured. Responsibility for both attacks was claimed by groups within the umbrella al Qaeda in the Islamic Maghreb (AQIM). These attacks are more regional than before in two ways.

First, they reflect an ideology that goes beyond borders. The back-to-back assaults are noteworthy for being directed against Westerners — the "far enemy" — and are seemingly untied to local grievances. Strategically, they are part of an intra-jihadist war ongoing between al Qaeda and the Islamic State in Iraq and Syria (ISIS), each seeking the mantle of responsibility for global jihad. But unlike attacks against Malian peacekeepers or the Nigerian military, they do not achieve any tactical objectives. In this sense, they are a striking departure from past terrorism in the region. Indeed, before November 2015, the last major attack directed against Westerners in West Africa occurred in Nigeria in 2011, when Boko Haram bombed the United Nations headquarters in Abuja. Even then, analysts scratched their heads as to why the group attacked an international target. Aside from hostage-taking for ransom (a money-making behavior), targeting foreigners fell outside the norms of the region's terrorist groups.

Second, the latest attacks are manifestations of regional dynamics, not domestic ones. When violent Islamist extremism struck Burkina Faso, it surprised many, and some theorized that militants shifted their attention to the country after fleeing France's intervention in northern Mali. Similarly, when gains were made against Boko Haram's territory in Nigeria in 2015, the terrorist group stepped up its activity in neighboring Chad, Niger and Cameroon. And all of the region's conflicts has been supercharged by a free-flowing arms trade. Sometimes weapons are captured from domestic stockpiles, but more often they are smuggled from elsewhere. The long-simmering stirs for independence in northern Mali boiled over in 2012 partly due to an influx in arms after the downfall of Libyan strongman Moammar Gadhafi and his weapons stockpiles in 2011. More recently, Sudan has become a cheap supplier of arms to West Africa.

West African terrorists now increasingly exploit the area's porous borders to trade and survive, which has in turn expanded their scope of operations. The danger and difficulty of this new reality is seen in Nigeria. Large swaths of land were reclaimed from Boko Haram in 2015, and President Muhammadu Buhari declared the group "technically defeated" by that year's end. But suicide attacks continued to target local civilians. Of course, total "defeat" of a terrorist groups is less clear than with enemy armies; terrorists can simply melt into the population and regroup in a less-governed area in the region. Increasingly, such groups are taking advantage of poor West African border security and international coordination to do this.

The United States has acknowledged the importance of regional considerations in West Africa. It launched the Trans-Sahara Counterterrorism Partnership in 2005, bringing together 10 countries for a multiyear, interagency program aimed at "building resilience" to radicalization, building counterterrorism capacity and improving regional security cooperation. But the partnership did not stop al Qaeda from seizing northern Mali for most of 2012. And when France led the charge to take back the region in 2013, only a U.S.-trained group from Chad took part in the initial offensive — despite Algeria, Burkina Faso, Mauritania and Niger actually bordering the affected area. The U.S.-led partnership had proven effective in building capacity, but less so at boosting regional security cooperation or intelligence-sharing. Since then, the U.S. has opened two drone bases in Niger in line with expanding intelligence collection in the region, and Americans reportedly participated in ending both the Bamako and Ouagadougou terrorist attacks. Yet such tactical assistance, while admirable, can accomplish little without complementary cooperation among the states in the region. (Some have even posited decapitating drone strikes only worsen terrorist diffusion.)

To effectively diminish the remaining terror groups in West Africa, the region's states will have to invest in cooperation, especially in policing and border security. Traditional military forces can — and have — "defeated" terrorist groups to an extent, but preventing asymmetric market bombings and hotel attacks requires a different response. Intelligence must be shared so that military and law enforcement can anticipate movements and apprehend militants in coordination, as well as work to interrupt their financing, internet recruitment efforts, and movement of fighters and arms. Perhaps "fusion centers" could place multinational military, police and customs officials in border areas in one complex, and international assistance could strengthen regional collaboration at the same time as various capacities.

Fortunately, there is a history of regional cooperation in West Africa. In 1990, the area's economic community formed a multilateral armed force, the Economic Community of West African States Monitoring Group (ECOMOG), which intervened in conflicts in Liberia and Sierra Leone with some success. Cooperation has continued in one form or another ever since. The 2015 joint offensive against Boko Haram included Nigeria, Niger, Benin, Cameroon and Chad, with soldiers often fighting outside their own national boundaries. These forces have had mixed success, with external factors like corruption, governance, military professionalism and civilian relations sometimes affecting their success. Military action cannot fully eradicate AQIM or Boko Haram, but the cooperation such joint forces exemplify will be a necessary part of any template for future counterterrorism efforts in West Africa. The alternative is a tragic whack-a-mole, with terrorists moving around the region and local civilians paying the price.

As the United States and its partners consider the recent terrorist attacks in West Africa, and the longtime challenge of Boko Haram and AQIM, it should not overlook the value of investing in strengthening regional cooperation and border security. These capabilities will help address terrorist threats in the short- and long-term while developing security partnerships that can contribute to stabilizing an often fragile region.

Rettig is a research associate at the Africa Center for Strategic Studies. All views expressed are those of the author and do not reflect an institutional position by the Africa Center or the Department of Defense.