Historian Kevin Kenny implies that a better world might have come had we not lost the "peaceable kingdom" supposedly promised in William Penn's dealings with Pennsylvania's Native Americans but undone by the bloodletting of land-grabbing settlers.

But Kenny does more than speculate on what might have happened had Penn's promise worked as the lodestar of Indian-European relations and Colonial settlement.

His account of violence, ethnic and religious rivalries, incompetent and self-destructing government, complicated alliances and imperial ambitions in the 18th century points to fundamental contradictions with those charged with realizing a "peaceable kingdom."

Kenny reveals how self-interest overrode the public good, with hell to pay for all concerned. In that regard, it rings true today as cause and consequence of Pennsylvania's persistent problem:

How to cultivate the necessary "common weal" to create a commonwealth.

Kenny begins and ends his absorbing, if dense and sometimes tangled, narrative with accounts of the extralegal violence of the Paxton Boys.

These Ulster Presbyterians from the frontier murdered Conestoga Indians in December 1763, then marched on Philadelphia early in 1764 to roust other native tribes under the protection of the Pennsylvania government.

During the American Revolution, the Boys ended up taking scalps and seizing land in northeastern Pennsylvania, raising the flag for the liberty to do what they wanted and take what they could get by threat and force.

Such violence, Kenny shows, largely went unpunished and thus begat more violence, the brutal product of an aggressive colonialism.

Penn's own interest in orderly settlement encouraged him to respect native interests enough to promote peaceful relations, but Penn's sons gave up their father's Quakerism to become Anglicans and abandoned his Indian policy.

They saw Pennsylvania as a commodity rather than a "holy experiment." But, as Kenny makes clear, effective government unraveled, the frontier collapsed into "anarchy," and violence ruled the day.

This book should remind us how much creating "facts on the ground" can defeat ideals and turn practices into policies. The Pennsylvania experience shows, too, that "ethnic cleansing" and a world view constricted to an almost tribal self-interest are hardly the exclusive province of the Balkans, the Middle East, or other troubled places beyond America's shores.