“She wanted to create a better world and would do everything in her power to do that.” The words of Anna Campbell’s father on her death in Syria convey the heartbreak any parent would feel. She was, he said, “young, idealistic, passionate, brave, determined”. He was “in pieces”.

Campbell’s brigade, the YPJ, is the women’s volunteer wing of the Kurdish resistance, regarded variously as freedom fighters or terrorists, Assad-backers or anti-Isis guerrillas. It hardly matters in the maelstrom of the modern Middle East. The defence of the Syrian city of Afrin against the Turks was by all accounts a hopeless cause, with rumours that the YPJ was left in a suicidal position by the Kurds, in the hope of garnering sympathy for its cause.

The British government pleads with its citizens to avoid this lethal theatre. It cannot extricate them if in trouble, nor can it tell on which side they may find themselves fighting. It is Isis versus Assad versus Syrian rebels versus Turks versus Kurds. A Briton on the “wrong” side risks being executed by an RAF drone, or imprisoned on return as a presumed terrorist. The idea of “making a difference” – that cliche of today’s employment culture – is absurd.

Yet throughout history people have warmed to the sentiments expressed by Campbell’s father. Eleanor of Aquitaine went on crusade to Syria. Byron went to liberate Greece. Undergraduates fought in the Spanish civil war. The urge to step outside our comfort zone, to find a cause worth fighting for, lies deep in the human soul.

The government must be right to warn its citizens when they run a severe risk, and inform them of the true nature of the causes to which they may be giving their lives. The sheer ignorance of the outside world that blights British education is appalling. Campbell was a trained plumber, a skill she could surely have used to make a difference to aid projects worldwide. Killing Turks in the rubble of Afrin seems a bizarre outlet for her talents.

But no man, or woman, is an island. Humanitarian sympathy is not a defect. It is hard not to accept a father’s sincerity, and hard not to warm to the adjectives he applies to his daughter’s memory. That young people want to travel abroad and identify with the struggles of others is not to be condemned. That they can leave a comfortable country and find fellow-feeling for those in misery is good. We might wish that such passion be directed to more productive ends, but the choice is not ours to make. Ours is not to reason why.

• Simon Jenkins is a Guardian columnist