These individuals, who have been warned by the Ukrainian officials, are taking advantage of Ukraine's International Legion in order to get training in flying first-person view (FPV) drones—a tactic now being used on a large scale by participants at its current conflict.

Ukraine is said to have received intelligence saying that people connected to Mexican cartels had joined up with Ukraine's International Legion, including from Mexico's equivalent of the U.S. Federal Bureau of Investigation (CNI), according to reports in Ukrainian media.

The CNI cautioned that this combat-drone knowledge, picked up in Ukraine, could now be turned against both law enforcement and rival gangs at home in Mexico. There have been reports of such cases already having occurred.

Security Agencies Investigating Infiltration
Ukrainian services, the Security Service of Ukraine (SBU) and the Main Directorate of Intelligence (HUR), have started investigating a number of foreign fighters fighting in the International Legion.

Some of them are thought to be involved in clandestine activities across the battle-scarred Donbas and Kharkiv, where Russians still control part.

To circumvent these checks, individuals linked to the cartel are believed by investigators to be using private military contractors to enter Ukraine's forces. This might have enabled them to escape the closer examinations involved in formal recruitment.

European countries, including Poland and Bulgaria, have also launched their own investigations amid similar concerns.

Hostile Foreign Fighters from Both Sides of the War
Foreign fighters have been taking part on both sides of the conflict since Russian forces launched a full-scale invasion of Ukraine in February 2022. Ukraine's International Legion is a loose collection of international volunteers who support its long, grinding fight against Russia.

At the same time, Russia has been accused of relying on foreign fighters from many countries to keep down its own battlefield casualties. Some of these recruits reportedly come from North Korea, while others are lured through online ads that promise desperate people financial relief.

The participation of foreigners in the Ukraine war raises difficult questions, particularly as suspicions rise that combat and military knowledge acquired on Ukrainian battlefields will be utilized for reasons far from the defense of Ukraine.