More than three million people died, some say, in one of the most violent and bitterly fought conflicts in the region in recent decades.
The idyllic scene in Maine is the Seeds of Peace summer camp, where hundreds of teenagers from some of the world's most bitterly polarized conflict regions, including the Middle East and South Asia, converge each year for a remarkable experience.
Alvaro de Soto, the just-retired UN coordinator for the Middle East, has warned that international hostility to the Palestinian Hamas movement, now fighting in the bitterly escalating civil conflict in Gaza, could have grave consequences by persuading millions of Muslims that democratic methods do not work.
Bitterly disappointed that the conflict was, in the end, settled by diplomacy, Massu became convinced that some French politicians were ready to abandon the true interests of their country.
My personal dream was to stand beside my husband and witness the end of a conflict that bitterly divides our peoples; to see the face of Yitzhak when peace shifted from paper into the living rooms of ordinary citizens.
Many of them view their quest for self-determination through the prism of the Arab-Israeli conflict and bitterly accuse the Turkish government of championing the Palestinians and defending the militant group Hamas while turning its back on its own minorities.
Unfortunately, promise has a way of fading quickly, and bitterly, in the Kashmir conflict.
Education for building peace For years, Côte d'Ivoire has been bitterly divided by a conflict fuelled by ethnic divisions.
In Shiite and Sunni mosques, some clerics called for forgiveness, while others wept bitterly over losses in the conflict or warned of more to come.
Rebels take control of eastern Aleppo, setting the scene for one of the most bitterly fought battles of the conflict.
