Amid a Russian-declared ceasefire marking Orthodox Christmas, Yevgeny Prigozhin, founder of the Russian mercenary company Wagner Group, called for Russian and Wagner forces to capture the city of Bakhmut in Ukraine’s Donbas region because of the logistical benefits of its “underground cities.” The Wagner Group has contributed a significant number of troops to Bakhmut, many of whom are ex-convicts Wagner recruited on the condition that Russia will erase their criminal records after six months of service. This has led to mass casualties (1,000 killed between late November and early December), with many of these recruited convicts being sent to the front line to identify Ukrainian positions for later attack.

Bakmut’s “underground cities” are a network of salt and gypsum mines with the ability to hold troops, tanks, and infantry fighting vehicles at a depth of 80-100 meters, according to Prigozhin. The city itself provides a logistical hub close to two larger Ukrainian cities, Kramatorsk and Sloviansk, and hosts intersections of road and rail supply lines. But despite these benefits, the Bakhmut offensive is “strategically unsound,” says Michael Kofman of the U.S.-based Center for Naval Analyses think tank, “given weak offensive potential and no prospective of breakthrough even if the city is captured.” Polish military analyst Konrad Muzyka agreed, claiming that the city has little strategic value at this stage of the war because Ukrainian forces have fortified the surrounding area. Nevertheless, Russian attacks on Bakhmut have devastated the city, reducing the city’s population from 70,000-80,000 people pre-war to only 10,000.

Prigozhin’s motivations for taking Bakhmut may stem from the mines’ monetary value, a White House official suggested, and according to Reuters, Prigozhin would secure political capital for supplying troops to the frontline of a successful campaign. Both are in line with Wagner Group’s history of war profiteering; in 2020, the U.S. Treasury Department sanctioned Prigozhin for financing his company’s exploitation of African countries. By supplying troops to obtain resources in nations including Libya, Mali, Sudan, and the Central African Republic, as well as Syria, Wagner has supported Russian corporations’ extraction of resources such as oil, gold, and diamonds.

As a private corporation, Wagner’s goal in war time is to profit. The use of convicts in Bakhmut displays this incentive structure, as Prigozhin ignores the human cost of the attack to achieve control of Bakhmut’s mines. And because Wagner nominally operates independently as a private military corporation (P.M.C.), the Kremlin can distance itself from Wagner’s activities while still maintaining its military resources when needed. “They may well have interests there. But … that has nothing to do with us,” a Kremlin spokesperson said when asked about Wagner’s behavior in Mali.

The Wagner Group operates in an array of different countries, but its activities remain the same. The group assists foreign governments through providing security services and mercenary force to retake territory from rebel groups, granting its client government more control over the territory. In exchange, this government grants Russian corporations mining concessions – an important privilege, because many of the countries Wagner operates in are resource-rich. Wagner’s supplemental role in the Ukraine invasion differs from its usual operations in Africa; Wagner soldiers in Ukraine are commanded by Russian military officers, according to Ukraine’s G.U.R. defense intelligence service, and are integrated into Russia’s military logistics chain. However, Wagner – and its founder, Prighozen – still maintain the goal of profiteering in Bakhmut.

The assault on Bakhmut displays the issues associated with the use of mercenary groups and P.M.C.s (the distinction is negligible) in combat. Where P.M.C.s prioritize objectives, such as control over natural resources, that will create a profit for their company, national militaries are more beholden to the public. (This is the case even in an authoritarian state such as Russia, where popular anger has been expressed through protests.) A national military is incentivized to focus on strategic objectives and minimization of casualties. Wagner, meanwhile, has seized upon Bakmut for the potential profit in its mines, regardless of the lack of strategic benefit the city gives Russia at this stage of the war.

In addition to an emphasis on natural resources, the profit incentive also encourages P.M.C.s to prove themselves to their benefactors in order to maintain their relationship with the contracting government. This pressure to display their capabilities with excessive violence incentivizes P.M.C.s to commit human rights violations. Wagner has been accused of many such violations, including in the Central African Republic, where a U.N. Security Council panel concluded in June 2021 that Wagner troops acting as instructors participated in indiscriminate killing and looting.

National militaries commit these same atrocities, but their institutionalization means that they have less incentive to take such drastic steps, and when they do, there are more mechanisms to hold them accountable. When U.S. personnel and employees of the Titan and C.A.C.I. firms tortured detainees at Abu Ghraib prison during the 2004 Iraq war, a U.S. Army investigation revealed that 36% of the abusers were contractors. Despite this, while 11 U.S. soldiers received convictions, none of the private contractors were charged for their crimes.

The lack of accountability also extends to the deaths of the contractors themselves. The same private contractor status that allows nations to avoid admitting responsibility for the human rights abuses of the P.M.C.s they’ve hired also allows the benefactor nation to avoid recognizing the price paid by the soldiers it sent into conflict. “[T]here was no outcry whenever contractors were called up and deployed, or even killed,” former Brookings Institute Senior Fellow Peter Singer noted in a 2007 report on the American P.M.C. Blackwater. “If the gradual death toll among American troops threatened to slowly wear down public support, contractor casualties were not counted in official death tolls and had no impact on these ratings.”

The international community has taken some steps against the use of mercenaries. In 1989, the United Nations General Assembly affirmed that “the recruitment, use, financing and training of mercenaries should be considered as offences of grave concern to all States and that any person committing any of these offences should be either prosecuted or extradited.” However, only 35 states ratified the United Nations Mercenary Convention in 2001, with the U.S. and Russia both counting among the countries refusing to ratify the document.

The world must take further action to prohibit hiring private militaries to fight a nation’s war. A P.M.C.’s flexible relationship with its client government incentivizes the use of excessive force and prevents nations from taking responsibility for their crimes in the name of putting stolen resources into the hands of war profiteers. Sanctioning Wagner Group for its role in the invasion of Ukraine is a positive step. However, we must go further and wholly denounce the use of mercenaries.