Operation Contenção, carried out in the Alemão and Penha complexes in Rio de Janeiro in October, left around 100 people dead and prompted allegations of extrajudicial executions of civilians by police and military forces. This makes it the deadliest police operation in Brazil’s history. According to Governor Claudio Castro, the aim of the operation was to contain the territorial expansion of the Comando Vermelho (CV)—one of Brazil’s most powerful criminal groups—which his government had declared a narco-terrorist organization. The CV did not suffer a major defeat as a result of the operation, and the deployment of approximately 2,500 military and police personnel, drones, and armored vehicles, along with the scale of casualties, was widely criticized by human rights organizations.

Across Latin America, conflict between state forces and illegal armed groups such as guerrillas, paramilitaries, and drug-trafficking organizations has intensified over the past few decades. As a result, even though the region has no interstate wars, it suffers from some of the highest levels of homicidal violence globally.

The expansion of organized crime and the hardline anti-crime policies framed within the “War on Drugs” paradigm have contributed to increased instability across the region, transforming some of its cities into de facto war zones. Over the past two and a half decades, states have regularly employed urban combat tactics to reassert territorial control. Recent examples include Mexico (in Michoacán and Ciudad Juárez since 2006 and 2008, respectively), Colombia (Operation Orion and Operation Phoenix in Medellín in 2002 and 2008), Ecuador (in Guayaquil in 2023), Brazil (in the Alemão and Penha neighborhoods of Rio de Janeiro since 2007 and in Jacarezinho in 2021), Venezuela (Operation Gran Cacique Indio Guaicaipuro in Caracas in 2023), and Haiti (in Port-au-Prince since the recent escalation of gang violence).

Despite the theoretical debate over whether events such as those in Rio de Janeiro meet the threshold of a non-international armed conflict under Article 3 of the 1949 Geneva Convention, developments across the region confirm what experts have been warning about in recent years: the nature of warfare is changing. John P. Sullivan argues that conflicts between “gangs, militias, mafias, and drug cartels on one side and State security services, police, and the military on the other” are becoming more common, and cities have increasingly become strategic targets for anti-crime operations.

What happened in Rio’s favelas is a daily reality in many other Latin American cities where millions live under violent hybrid governance imposed by criminal or paramilitary groups while also suffering the consequences of militarized state responses. Urban operations therefore are the focus of multiple legal and moral dilemmas that are incompatible with a liberal state. For example, to what extent is it legitimate for the state to use its monopoly on violence against domestic targets when doing so may harm civilians? And what kind of training do military and security forces need to operate in densely populated urban centers?

In Future War in Cities: Rethinking the Liberal Dilemma, expert Alice Hills offers several fundamental insights into the dynamics of urban warfare and intrastate urban conflicts. First, drawing on the cases of Grozny and Sarajevo, Hills shows how urban environments often magnify and intensify the cost of conflict. In the case of Rio de Janeiro, police operations caused brutal damage and high social costs to the already fragile infrastructure of marginalized neighborhoods such as Alemão and Penha. Road closures, service suspensions, and logistical paralysis have caused fiscal and tax losses for both the state and the municipalities.

Second, in urban conflicts, belligerents often attack civilians or use them as human shields. Local communities are often trapped between opposing forces, unable to reach safe havens and exposed to lethal force. As a result, it is sometimes the affected communities that organize locally to protect themselves. For example, in Rio de Janeiro, there are apps that alert people in real time about where shootings are taking place.

Third, a single mission in a city often requires multiple simultaneous and sequential actions. To reduce the impact of this high-intensity urban conflict on civilians, armed forces need high levels of military proficiency. However, armed forces are rarely trained or equipped to fight in urban areas. Moreover, most states do not develop a plan grounded in international humanitarian law to protect civilians affected by urban warfare.

Fourth, post-conflict urban reconstruction poses enduring challenges. During and after urban operations, security forces and local governments must address civilian displacement, medical care, and the reconstruction of critical infrastructure. Comparative experience indicates that few governments have put the safety of the population first during these reconstruction efforts.

The lessons that emerge from Brazil bring to the fore the critical situation of Latin American states confronting hybrid threats and urban conflicts. Today, organized crime is the main threat to human security in Latin America and the Caribbean. As César Niño argued in a recent article, “It is paradoxical that people do not fear a nuclear attack or the invasion of another state, but rather their fears lie in the everyday—in crime, massacres, confinement, kidnapping, and extortion.”

Perhaps nowhere is this more true than in Haiti, where around 90% of Port-au-Prince is controlled by gangs, and their influence is spreading to other regions of the country. Haitian police have been resorting to increasingly militarized methods, including drone strikes against alleged gang members that have killed hundreds of people, including children, since March of this year with support from an American private security contractor. International intervention in Haiti is also shifting toward a more militarized approach with the replacement of the Multinational Security Support (MSS) mission with a Gang Suppression Force (GSF) authorized by the UN Security Council in September. While many see the GSF’s more offensive approach as necessary, it also raises concerns about the potential for high civilian death tolls, as seen in so many other urban conflicts across the region.

As more cities across Latin America become battlegrounds, states have an obligation to put people’s safety first. This requires preparing for urban operations by developing civilian harm-mitigation policies with contingency plans, including for evacuating civilians and maintaining essential communications and services. It also requires ensuring that security forces are tactically, legally, and morally prepared to operate in urban environments. Without such measures, urban operations will continue to take an unacceptably high toll on civilians.