What can a train ride tell you about a city? Quite a lot in Jerusalem, where the city's new light railway trundles its way along the contentious green line and many holy sites

The four teenage boys on the Jerusalem light rail belonged to the global brotherhood of lads. Dressed in jeans, hoodies and trainers; they slouched in their seats, lanky legs stretching halfway across the carriage, joking around, rolling an empty water bottle between their feet.

Nearby, another passenger was visibly irritated. He was perhaps 10 or 15 years older, wearing a neat beard, sunglasses, shorts and a faded t-shirt and drumming his fingers on the magazine of a battered assault rifle lying across his lap. The man was Israeli, possibly from the settlement of Pisgat Ze'ev where he had boarded the train. The boys were Palestinian, most likely from Beit Hanina, an Arab neighbourhood.