WASHINGTON -- "Innocent until proven guilty" is a favorite, if sometimes ignored, American trope.

We are reminded of that once again with charges being dropped against two Marines in the so-called "Haditha Massacre" of November 2005. As well, we are reminded of the difficulty in applying civilian perceptions and standards to military conflict.

Those exonerated, Lance Cpl. Justin L. Sharratt and Capt. Randy W. Stone, were among eight (seven Marines and one sailor) charged in the deaths of 24 Iraqi civilians after a roadside bomb had killed a Marine.

Sharratt, 21 at the time of the incident, was charged with three counts of unpremeditated murder and faced life imprisonment. Stone, a military attorney, was charged with two counts of dereliction of duty and one count of violating a lawful order for allegedly failing to properly investigate the killings.

Other Marines involved in the incident, including one charged with 13 counts of unpremeditated murder, are either awaiting hearings or dispensation of their cases.

Haditha is one of those wartime horror stories that rivets and divides nations. There's no question that Iraqi civilians, including women and children, were killed during what appears with hindsight -- and from the comfort of American living rooms -- to have been a gratuitous rampage.

Allegations also were made that the U.S. military tried to cover up the killings and mischaracterized them as collateral damage during the roadside bombing and ensuing skirmish, rather than as the result of a "shoot first, ask later" order.

From a civilian perspective, the case seemed clear-cut. How does one ever justify intentionally killing civilians? The answer is: We don't.

Americans struggle with the horror of civilian casualties, while insurgent and terrorist forces in Iraq devise ways to effect more, not fewer, civilian deaths. What we deplore -- and punish -- they celebrate. And replicate.

There is a difference, one that is both our strength and our weakness. Though some Americans, like other mortals, are capable of inhumanity, our national conscience compels us to examine the impulses that degrade our character and purpose.

Our attention to moral warfare -- always our goal, if not always met -- also nourishes our enemies, who suffer no such burden. They know that demoralization and flagging commitment tend to follow our moral introspection.

War does not become us.

We simply don't like killing as much as our enemies seem to, though you wouldn't know it to have read early reactions to Haditha. After Time magazine first reported the incident, sparking an investigation, other breathless stories followed that all but convicted the Marines of atrocities. Continued...