After two years the civil war in Syria shows no immediate sign of coming to an end. Though exact numbers are difficult to determine it is likely that hundreds of thousands of people have been injured or killed. Millions more have been displaced and communities across the country have been irremediably scarred by fighting that has seen homes, schools, businesses and hospitals destroyed. Yet those opposed to the Assad regime show no signs of faltering. Something keeps them at the front line - even though they are outgunned and often desperately short of everything from ammunition to medical supplies.