Last summer, we traveled to India with a team of West Point faculty and cadets to study the 2008 Mumbai terrorist attacks. Those attacks revealed lessons about the challenges of urban warfare. They also highlighted—as we learned during our two weeks there conducting dozens of interviews, site visits and detailed research—a number of lessons about the use of proxies in the 21st century. Combined with lessons we also learned during a similar cadet and faculty research trip to Ukraine the year before, our research yielded important conclusions that should inform the way the U.S. Army conceptualizes the role of proxies in modern war.

When 10 Pakistan-based terrorists infiltrated Mumbai and laid siege to targets across the city in November 2008, they brought the city of 18 million to a standstill for nearly four days. The world watched, shocked by the duration and impact of the attack from so few terrorists with limited training.

Support From Pakistan

Based on intelligence gathered before, during and after the attacks, it was determined that the terrorists were members of the Islamist militant group Lashkar-e-Taiba and had received support from Pakistan’s Inter-Services Intelligence (ISI) directorate. Lashkar-e-Taiba has a history of employing terrorism as a means of influencing ongoing national disputes over the Jammu and Kashmir regions of India. The terrorists involved in the Mumbai attacks came from impoverished areas of Pakistan and had little education. Many were given to Lashkar-e-Taiba by their parents with promises of monetary payment once their children completed, and were almost inevitably killed during, their mission.

Beyond basic weapons skills, ISI provided specialized support to the terrorists. Yet what made the Mumbai attack so unique and deadly was that the terrorists were remotely commanded and controlled throughout the operation by handlers in Pakistan who used satellite phones to give commands to the attackers. The handlers even monitored social media and live news coverage to provide real-time intelligence and changes to the plan. Everything about the terrorists’ operation was designed to disguise their origin, from the boats they used to approach Mumbai’s shore to their Western clothing and haircuts to local religious wristbands.

A little over five years after the Mumbai attacks and nearly 3,000 miles away, proxies took a central role in yet another catastrophe as the world watched. In its annexation of Ukraine’s Crimea, Russia supported criminal groups and deployed fighters to realize its objectives. During the conflict that began shortly after in the Donbass region of eastern Ukraine, Russia has provided levels of support to separatists, ranging from military aid to outright command and control of these forces.

Yet Russia has also found that these proxies are sometimes difficult to control. On July 17, 2014, Ukrainian separatists shot down a Malaysia-bound civilian airliner with a Russian-supplied surface-to-air missile, killing 298 passengers and crew. While Russian President Vladimir Putin denied any responsibility, a Dutch-led joint investigation and evidence supplied by the online investigative journalism outlet Bellingcat indicated that Moscow had supplied the rocket used in the attack. As Russia faced greater international pressure to contain the conflict, especially after the downing of the airliner, Moscow carried out a series of purges of separatist leaders, presumably in an effort to ensure a degree of control over Russia’s proxies.

Understanding Is Important

Proxy warfare is not formally defined in Army doctrine—which deserves to be rectified—but broadly speaking, the term refers to the provision of financial support, weaponry, training or other material by a state to nonstate groups in exchange for the latter fighting on behalf of the state’s interests. Proxies may be used because a nation does not want to risk its own citizens or to provide plausible deniability of its involvement. Proxy forces can range from organized paramilitary outfits to decentralized militias to small terrorist cells.

It is important to understand the role proxies play in warfare for several reasons. First, many of our potential adversaries are using proxies—Russia in Ukraine and Syria, for example, and Iran in Iraq and elsewhere in the Middle East—as are partners with whom our relationship is sometimes difficult, like the Pakistani ISI’s support to militant groups in Afghanistan and India. Many of these proxies are challenging and even undermining U.S. military efforts, so we must better understand who they are and how to neutralize them. The future of great-power conflict will also likely include a proxy component.

Second, the involvement of proxies makes both the strategic and operational picture of conflicts murkier. This in turn raises the risk of proxies’ actions pushing the U.S. closer to a confrontation with a major regional power such as Russia or Iran.

Third, the U.S. has its own history of supporting proxy forces—not always with a successful outcome. The most dubious recent case is the $500 million the U.S. spent in 2015 to build what was intended to be a 5,000-man rebel force to fight the Islamic State group in Syria, which produced a mere five fighters before being shut down. Our support to mujahedeen fighting in Afghanistan in the 1980s was a short-term success—they played a large role in the Soviet Union’s decision to leave—but with negative long-term ramifications as some of these fighters subsequently formed the initial core of al-Qaida under Osama bin Laden.

Lessons Learned

The Mumbai terrorist attack was an extraordinary example of a nation-state supporting and enabling an attack against another state using proxy paramilitary fighters. Had phone communications between the terrorists and Pakistan not been intercepted and recorded, and, even more so, had all the terrorists died in the attack as planned, it would have been difficult for India to prove ISI’s complicity in the attack.

The cost of proxy warfare in the modern age has decreased, which means the tactic will likely be used more frequently in unstable regions like much of the Middle East and in contested territory like the Donbass region. The cost of military training for the Mumbai terrorists was relatively low in comparison to the impact of their attacks. In an age of extreme political instability, with new methods of disguising proxy forces such as deep fakes and social media disinformation campaigns, the political cost of covert proxy warfare will continue to decrease, meaning it is less risky for states to deploy these methods.

For the Army, conducting missions in operating environments that feature some degree of proxy involvement will become increasingly likely, to include in peer or near-peer competition. As Multi-Domain Operations continues to be refined as a concept, the presence of a range of proxy forces must also be envisioned. In such an environment, the intelligence warfighting function becomes a priority, and soldiers must become aware of proxies’ role and impact in their assessments during training and operations.

Institutionally, the Army must be prepared to conduct a range of missions in an era of proxy warfare.