The Institute for Strategic Dialogue in London has published a report asserting that over 100 Americans are fighting alongside anti-ISIS militias in Iraq and Syria, making up over a third of the foreign recruits for those militia groups.

“The report found that Americans are more prevalent in the groups than those from any other Western nation, with the U.K. following. Most of the volunteers are serving in Kurdish militias in Iraq or Syria,” ABC News reports.

The report found anti-ISIS recruits skew a bit older than the Islamic State’s average recruits, and many of them have military experience. A variety of motivations for their journeys to Iraq and Syria were collected by the Institute, ranging from a determination to halt the Islamic State’s atrocities, to religious solidarity with Christian minorities in the war zone, thrill-seekers, and military veterans who “may have had trouble adjusting to life in the civilian world after their service or felt more at home in a war zone.”

The report adds that some Western military veterans want to “consolidate the post-conflict reconstruction and stabilization that they contributed to in Iraq after 2003” — in other words, “finish the job” in Iraq and ensure the “death and suffering of civilians and fellow military personnel” was not in vain.

According to the report, the Kurds have been somewhat reluctant to put foreign recruits on the battle line, instead using military veterans as trainers and logistical support, while those without military experience tend to receive “low-level, menial tasks” away from combat.

After seeing the Institute for Strategic Dialogue report, NBC affiliate WWBT in Virginia found a local man, 27-year-old Kevin Hodge, who said he had traveled to Syria to fight alongside Kurdish militia. He said he contacted the Kurdish YPG through Facebook and arranged to have himself smuggled into Syria, where he received two weeks of training and was sent to the front lines.

Hodge said he was “inspired to make the trip after seeing coverage of ISIS on the news, specifically, how the terror group was driving people out of their homes.”

Most of the foreign recruits are male, but The Hill quotes one woman from the report:

This time last year I was a stay at home mom/wife. Even though I knew my marriage was up in flames I had still tried. I went through a very dark period in my life… After joining the Kurds and seeing the problems first hand in other parts of the world my priorities were set straight again. Thousands don’t agree with my choice and honestly I don’t give a damn.

Canada’s National Post notes the ISD criticized Western governments for failing to make it clear whether signing up with foreign anti-terrorist militias was legal.

“All governments should be explicit in their communications around anti-ISIS foreign fighters to ensure the legal position and possible sanctions are clearly set out. Law-enforcement measures and prosecutions then need to be applied consistently and proportionately,” the report urged.

The U.S. government “strongly discourages” American citizens from traveling to Iraq or Syria to fight ISIS, as The Hill observes. A warning issued by the State Department reads: “The U.S. government does not support this activity, and our ability to provide consular assistance to individuals who are injured or kidnapped, or to the families of individuals who die as a result of taking part in the conflict, is extremely limited.”

A disturbing tidbit from the ISD report cited by The Hill: While roughly a third of foreign recruits are fighting with the Kurdish YPG in Syria, and another 20 percent with the Kurdish peshmerga in Iraq, there are also a “handful” of foreigners fighting with unsavory groups like Hezbollah and Shiite militia units.