The Piligrims established a tradition of more or less peaceful coexistence with the Native Americans that lasted over fifty years. Why did that tradition collapse in the 1670s and what might have been done to prevent it?

The Pilgrims established peace with the Wampanoags around Cape Cod after they arrived in 1620. Their migration was followed by other migrations that brought increased English settlement to New England. For example, 20,000 Puritans came to the area during the Great Migration of 1620-1640 to escape religious persecution in England. They settled along the Connecticut River and the coast and were beginning to settle at points in between, causing increased pressures on the Native Americans in the region to give up their lands. In addition, the later settlers were not part of the original peace settlement that the Pilgrims had established with Native Americans.
In 1675, King Philip's War broke out between the English settlers and Native Americans, who were led by Metacom (also called King Philip), the son of Massasoit (who had lived peacefully alongside the Pilgrims). This war led to the horrific defeat of the Wampanoags and Narragansett tribes. As a result, the flow of English settlement over Native American lands in most of New England was unrestricted. The war might have been prevented if the English settlers had respected Native American claims to the land, but the English did not.