Foreign volunteer fighters in Ukraine face intense combat trauma with almost no support

They arrived in Ukraine with military training from Iraq or Afghanistan but without the institutional scaffolding that came with those deployments - no structured chain of command, no pre-deployment preparation, no guaranteed medical evacuation, no therapist waiting at the end. They were veterans of professional armed forces who chose to fight as volunteers in a conflict that offered none of the support systems they once took for granted.

A study published March 23 in the European Journal of Psychotraumatology examines what happened to them. The findings, from researchers led by Victoria Williamson at the University of Bath, describe a population caught between two worlds: too experienced to be naive about war, but too informal to qualify for the care systems designed for uniformed soldiers.

Drone warfare and trench fighting without preparation

The study involved 31 US and UK military veterans who volunteered with Ukrainian armed forces after Russia's invasion in 2022. All 31 completed psychological assessments, and 21 provided in-depth interviews about their experiences.

The combat they described differs substantially from the conflicts most Western militaries have fought in recent decades. Iraq and Afghanistan involved counterinsurgency operations with periods of relative quiet, structured rotations, and forward operating bases with medical facilities. Ukraine's front lines feature sustained trench warfare, constant drone surveillance and strikes, and grinding attrition that more closely resembles World War I than the wars these veterans had previously fought.

Many reported receiving little formal training or preparation from Ukrainian forces before being embedded into frontline units. Equipment quality varied. Medical care in the field was described as poor or nonexistent. Several participants had sustained physical injuries that went untreated during their time in Ukraine.

PTSD, moral injury, and alcohol

The psychological toll was severe. The study identified high levels of probable post-traumatic stress disorder (PTSD), common mental disorders, and alcohol misuse among participants. Quality of life scores were low.

Particularly notable was the prevalence of moral injury - the intense psychological distress that occurs when a person witnesses or participates in events that violate their core moral beliefs. Moral injury produces persistent feelings of shame, guilt, disgust, or anger that standard PTSD treatments do not always address effectively. The chaotic and informal nature of volunteer service in Ukraine, with unclear rules of engagement and limited command oversight, creates conditions ripe for morally injurious experiences.

Participants also reported turning to alcohol to manage their distress, both during service and after returning home. Without access to professional mental health care, peer support from fellow volunteers became the primary coping mechanism - a pattern that can sustain social bonds but does not substitute for clinical treatment.

Locked out of care systems on both sides

The study's most troubling finding may not be the psychological damage itself - that is expected given the combat conditions described - but the near-total absence of support. Veterans reported repeatedly seeking mental health care in Ukraine and being unable to access it. On returning to the US or UK, many were turned away from military healthcare systems because their service in Ukraine was voluntary and unofficial. Civilian mental health services placed them on long waiting lists or lacked expertise in combat-related trauma.

These volunteers fall into a gap. They are not active-duty service members entitled to military healthcare. They are not civilians who have never experienced combat. The existing support infrastructure in both countries was not designed for people who voluntarily embed themselves in foreign wars and return home with the same injuries as uniformed soldiers but none of the institutional recognition.

An estimated 3,000 Americans applied to join Ukraine's International Legion after the 2022 invasion, and a substantial number of UK veterans also traveled to fight. Reports suggest nearly 20,000 foreign nationals applied overall. The actual number who saw combat is smaller but not trivial, and each one who returns home carries the potential for untreated trauma that can ripple through families and communities.

How Ukraine's war differs from Iraq and Afghanistan

Williamson, who also serves as president of the UK Psychological Trauma Society, emphasized that the nature of combat in Ukraine is fundamentally different from other recent Western military engagements. In Iraq and Afghanistan, Western personnel operated within formal military systems with clear rules of engagement, structured command chains, established legal protections, and welfare support. They received preparation before deployment and support on return.

Volunteer fighters in Ukraine are effectively self-deployed. Training, leadership, equipment, and medical support vary enormously depending on which unit a volunteer joins and when they arrive. The result is a combat experience that combines extreme intensity with extreme unpredictability - two factors that multiply the psychological impact of warfare.

Thirty-one participants and an urgent signal

The study's sample size - 31 participants - is small, and the authors acknowledge this. Recruiting volunteers who have fought in an active conflict zone is inherently difficult. Some are still deployed. Some are reluctant to discuss their experiences. Some have cut ties with formal systems entirely.

The findings cannot be generalized to all foreign fighters in Ukraine, who come from dozens of countries with different military backgrounds and different reasons for volunteering. The US and UK veterans in this study had prior professional military experience, which may make their psychological profiles different from volunteers without military backgrounds.

But the consistency of the findings - high PTSD rates, high moral injury, high alcohol misuse, low quality of life, and systematic inability to access care - creates a signal that is difficult to dismiss as a quirk of small sample size. The authors argue that without coordinated and targeted support, these veterans risk becoming an invisible population whose mental and physical health needs go permanently unmet.

The study's implications extend beyond Ukraine. As new conflicts unfold globally, the phenomenon of self-deployed volunteer fighters is likely to recur. Building clinical pathways that recognize and serve these individuals before they disappear into the margins is, the researchers argue, an urgent priority.