Malcolm Nance — a former MSNBC analyst, counterterrorism expert, and Wynnefield native — announced Monday night on Twitter that he had joined the fight in Ukraine.

“I’m DONE talking,” read the post that featured a black-and-white photo of Nance, a West Philadelphia Catholic High School for Boys grad, in army fatigues holding up what appears to be a rifle.

In a television appearance on MSNBC Monday night from Lviv, Nance said he joined the International Legion for the Territorial Defense of Ukraine a month ago.

Ukrainian President Volodymyr Zelensky created the legion, which takes volunteers from other countries, days after the Russian invasion. A March estimate from the Ukrainian Defense Ministry cited some 20,000 people from more than 50 countries had volunteered, including 3,000 Americans.

Just how these forces are being deployed in Ukraine is unclear. Nance did not offer any specifics when MSNBC’s Joy Reid asked him what the volunteers have been tasked to do.

“We are here for one purpose and one purpose only and that is to protect the innocent people of Ukraine from this Russian aggression,” Nance responded, adding that he went to Ukraine to offer his skills.

A former Naval intelligence officer, Nance speaks multiple languages and has prepared special forces on how to deal with groups like ISIS. Nance is also the executive director of the Terror Asymmetrics Project, a terrorism think tank.

In his television interview, Nance said he’d spent time in Ukraine before the war and was motivated to join resistance efforts after his friends, who are in the Ukrainian army, described a dire situation where they were being “hit 500 times.”

In an interview with the Daily Beast, Nance explained he let his contract expire with MSNBC and “came right over.” An MSNBC Tweet confirmed Nance is a former employee.

In his media interviews, Nance has touted the legion’s volunteer efforts and described the volunteers as being there for the right reasons. But profiles of some volunteers highlight the challenges that come from recruiting a fighting force from all over the globe, including infighting brought about by a lack of structure and volunteers exaggerating their combat experience.

To join the legion, foreigners need to go to a Ukrainian Embassy with documents proving their military experience or service in law enforcement agencies. If approved, it’s recommended volunteers bring their own gear to Ukraine. Foreign soldiers don’t sign a contract until they reach the designated “collection point” in Ukraine.

Despite the Russian Defense Ministry’s warning in early March that foreign soldiers would be prosecuted as criminals at best, Nance shrugged off any suggestion that foreigners faced exceptional danger in Ukraine.

“They’re not going around hunting for American flag patches or to see who’s Black, who’s Asian, who’s Latino,” said Nance to Reid. “We’re a part of the Ukrainian armed forces.”