True enough, John. Worth adding that British Muslims appear to have fought on the Jihadi side in Afghanistan and Iraq, and then there was this from 2003:

A suicide bomber and his accomplice who murdered three people and wounded scores at a Tel Aviv bar yesterday carried British passports and travelled to Israel specifically to kill, according to local officials. Israeli sources said it was believed that the 21-year-old bomber, Asif Mohammed Hanif, travelled from Egypt to Gaza and then entered Israel. A second man who was allegedly carrying an explosive belt that failed to detonate was named as Omar Khan Sharif. Last night he was on the run. His British passport records him as born in Derby 27 years ago and entering Israeli through Tel Aviv’s international airport about a month ago. He then visited Gaza, apparently leaving the area a few hours before the attack.