Llangwm, in Pembrokeshire, west Wales, huddles around an inlet of the Cleddau Estuary. Sitting at the end of a minor road with nowhere else to go, it is isolated. This isolation has over many generations engendered a strong sense of communal self-sufficiency. With its church, two chapels, post office, pub, rugby and cricket clubs, school, an annual literary festival, choir, and a host of other societies, it is a very busy village.David Wilson lives...