The UK carried out a strike against one of its citizens in Syria, so they most certainly do use armed drones. https://www.theguardian.com/uk-news/2015/sep/07/u

The UK carried out a strike against one of its citizens in Syria, so they most certainly do use armed drones. https://www.theguardian.com/uk-news/2015/sep/07/uk-forces-airstrike-killed-isis-briton-reyaad-khan-syria https://www.theguardian.com/uk-news/2015/sep/07/uk-forces-ai... It was a US-built drone, but it was a British mission with British pilots.