Despite having no military experience, Jim Atherton, 53, of Tyne and Wear, has sold his car to buy weapons and has already come under mortar and rocket attacks.
The granddad, who before leaving for Iraq cared for rescued daschunds, said Special Branch had tried to persuade him to come home, but he believed his place was fighting jihadists.
Mr Atherton said his family had been devastated by his decision to join a Christian militia called Dwekh Nawsha, which means The Sacrificers. He now belongs to a unit which protects the Christian population of Iraqi villages such as al-Qosh.
He raised the £18,000 needed for travel and guns by selling his Sierra Cosworth, two motorbikes and a boat.
Mr Atherton, whose younger brother was killed fighting in Afghanistan, came across Dwekh Nawsha on the internet.
As a virtue, courage is the golden mean between cowardice and foolhardiness; I don't know if Mr. Atherton is courageous or foolhardy.
Dwekh Nawsha has its own Facebook page, of course, with some interesting photos and video, though it seems to be mostly in Syriac. And a YouTube channel with lots of videos but not much action. If Wikipedia is right:
The Dwekh Nawsha is a military organization created in mid 2014 in order to defend Iraq's Assyrian Christians from the Islamic State of Iraq and the Levant (ISIL), and possibly retake their lands currently controlled by ISIL.
Unlike the NPU which is independent of the KRG and Peshmerga, the Dwekh Nawsha operates in coordination with them.
Despite being led by the Assyrian Patriotic Party, most militiamen are not members of the party. Several foreign fighters have joined the Dwekh Nawsha; they include Americans and Australians.
Interesting times we live in.