From jungle guerrilla warfare to frozen trenches: why did they leave and will they ever return? The story of the Colombian soldiers choosing to fight in the war in Ukraine. 'We heard the Ukranian President’s SOS call" says Castaño, a soldier in his early 30s who paid for his own flight from Colombia to fight in the war in Ukraine. He's not the only one, Colombians are said to outnumber any other nationality of those foreigners who have volunteered to fight. They've even promoted a Colombian to the rank of Sergeant so he can help process the huge numbers of Latino recruits who don't speak any Ukrainian. Some soldiers we meet have already made a huge sacrifice for a country that’s not their own and are learning to walk with new prosthetic limbs. But they're not just drawn to Ukraine to help, a range of factors in Colombia have pushed many soldiers to leave, not least low pay and a feeling that a job in the Colombian Army is no longer worth it.

Marco Pereira travels around Ukraine talking to Colombian soldiers to find out why they have chosen to fight in a punishing war so far from home.

This episode of The Documentary comes to you from Assignment, investigations and journeys into the heart of global events.