International relations expert Dr. Renato De Castro warned Filipinos on Thursday against joining foreign armed groups, saying those recruited as mercenaries risk losing protection under international law.

De Castro, a distinguished professor of international studies at De La Salle University, made the statement in an interview with DAILY TRIBUNE’s digital show Usapang OFW.

He was reacting to reports that a Filipino, identified as Raymon Santos Gumangan, is being held by Ukrainian authorities, after being captured fighting alongside Russian forces.

“You can be executed right away if you’re caught as a mercenary, because you are not under or governed by the articles of the Geneva Convention,” De Castro said.

Ukraine released a video wherein Gumangan, who worked for a security firm in the Philippines, was shown saying he was recruited to do “logistics” jobs for the Russian side in its conflict with Ukraine.

Authorities said Gumangan is not registered with the Department of Migrant Workers or the Overseas Workers Welfare Administration, and that deployment of Filipino workers to both Russia and Ukraine remained prohibited.

Soldiers of fortune

De Castro said mercenarism predates modern warfare and is often referred to as the “third oldest profession,” involving so-called soldiers of fortune. 

Under the Geneva Conventions, mercenaries are not entitled to prisoner-of-war status and may be treated as spies, he said, adding that Ukraine’s handling of the case also has diplomatic implications.

“A few months ago, the Russian Embassy accused the Philippines of allowing Filipinos to be recruited by Ukrainians as mercenaries,” De Castro said, noting that Ukraine may now be using the case to put Russia on the spot.

Armed Forces of the Philippines sources said Gumangan is not a former member of the military.

De Castro said the Philippine government’s legal options are limited, as mercenary activity is undertaken at personal risk, but humanitarian appeals may still be pursued.

Labor officials had reiterated their call for Filipinos to verify overseas job offers through the DMW to avoid illegal recruitment and dangerous deployment.