While illegally crossing the border between Iraq and Syria, Peter Douglas, a Canadian, was adamant that his incursion was for humanitarian reasons — to help the people of Syria.

Douglas is one of a growing band of foreigners to dodge authorities and join the fight against the Islamic State militants who have slaughtered thousands and seized vast areas of Iraq and Syria, declaring an Islamic caliphate in the territory under their control.

Many of these fighters say that they are there for humanitarian reasons, but acknowledge that their decision to take up arms on behalf of the Syrian people will not be viewed as such by some.