TENNA, Iraq — Iraq’s dwindling Christians, driven from their homes by attacks and intimidation, are beginning to abandon the havens they had found in the country’s north, discouraged by unemployment and a creeping fear that the violence they had fled was catching up to them.

Their quiet exodus to Turkey, Jordan, Europe and the United States is the latest chapter of a seemingly inexorable decline that many religious leaders say tolls the twilight of Christianity in a land where city skylines have long been marked by both minarets and church steeples. Recent assessments say that Iraq’s Christian population has now fallen by more than half since the 2003 American invasion, and with the military’s departure, some Christians say they lost a protector of last resort.

Their flight is felt in places like the wind-scoured village of Tenna, which has sheltered dozens of Christian migrants over the past nine years. The families fleeing Baghdad’s death squads and bombings found safety here beneath the hulking mountains, but little else besides poverty, boredom and cold. Villagers estimate that half of the 50 or so Christian homes are now empty, their families abroad.

Walid Shamoon, 42, wants to be the next to leave. He said he left Iraq’s capital in January 2011 after a confrontation with Shiite militia members set off a nightmare of escalating death threats and an attempt on his life. A brother had already been killed in a mortar attack six years earlier, so he said he quit his contract job with the Australian Embassy, giving up a $1,500 monthly salary, and came here.