American statists and imperialists are coming up with all sorts of explanations to explain the epidemic of suicides among U.S. military personnel. The most popular explanations are war stress and stress at home.

I’ve got another possible cause: guilt, arising from the wrongful killing of other human beings.

Consider Iraq. Neither the Iraqi people nor their government ever attacked the United States or even threatened to do so. They had nothing to do with the 9/11 attacks. When U.S. soldiers invaded Iraq, they were the aggressors. At worst, every single Iraqi killed by U.S. forces was simply defending his country against an unlawful invasion by the military forces of a foreign power.

U.S. soldiers in the initial invasion force undoubtedly convinced themselves that they were killing Iraqis under the notion of self-defense, telling themselves that they were protecting the United States from an imminent WMD attack.

At some point, however, reality set in. There were no weapons of mass destruction. Yet, countless Iraqis had already been killed by U.S. soldiers.

At that point, did the U.S. government apologize for this grave mistake? Did President Bush order an immediate withdrawal from the country?

No.

Once it was determined that Saddam Hussein had in fact destroyed his stocks of WMD, the U.S. government nonetheless decided to remain in Iraq, calling on the troops to enforce a brutal occupation, one that necessarily involved killing more Iraqis.

At that point, any semblance of the “self-defense” rationale disappeared for U.S. troops killing Iraqis. Any soldier who killed an Iraqi after that point knew, with 100 percent certainty, that the person he was killing was entirely innocent of any actual attack or threatened attack on the United States, including 9/11 and the WMDs.

Throughout the occupation, people have called on U.S. forces to be more careful about killing civilians. The implication has been that it’s okay for U.S. forces to target insurgents or combatants but needed to be careful about “collateral damage.”

Not so. The U.S. government had no right whatsoever, legal or moral, to be in Iraq, and especially not after it was conclusively determined that Bush had been wrong about the WMD threat. That means that U.S. soldiers had no right, legal or moral, to kill any Iraqi, not even Iraqis who were defending their country from an unlawful invasion.

Suppose a U.S. soldier says, “But if they’re shooting at me, I have a right to shoot back in self-defense.”

Not so. If a burglar enters a home and is shot at by the homeowner, the burglar cannot, legally or morally, shoot back at the homeowner and claim self-defense. Since the burglar has no right to be in the home, his only option, legally and morally, is to withdraw from the home without firing back at the homeowner.

The situation is no different with the U.S. government. It had no right to invade Iraq. It had no right to occupy Iraq. U.S. soldiers had no right to kill (or maim, incarcerate, torture, abuse, rape, or execute) one single Iraqi — not civilians, not insurgents, not even members of Iraq’s armed forces.

Statists and imperialists have come to defend the killing of Iraqis under a mathematical formula. They say that Iraqi deaths have been worth it because Iraq is now, they claim, a better place than it was under Saddam Hussein. That’s, of course, a proposition that might be disputed by many Iraqis, and most likely the dead would have preferred to be alive, even if Iraq was a worse place without the invasion and occupation.

But consider the moral issue involved here. The statists and imperialists are telling U.S. soldiers that it’s okay for them to kill other human beings in the attempt to bring a better life to the rest of the citizens in that society.

What moral or religious creed justifies killing another human being under that sort of welfare rationale? Certainly not Christianity.

Aggravating this entire situation is the fact that U.S. soldiers have killed people in a war that violates the U.S. Constitution, the document that soldiers took an oath to support and defend. It is undisputed that Congress never declared war on Iraq, as the Constitution requires.

Of course, no soldier will ever be criminally prosecuted for the killing of Iraqis. But immunity from criminal prosecution cannot protect a person from the persecution of his own conscience. While the worst sociopathic murderers can somehow bury their consciences and never seem to suffer guilt or remorse when they kill people, most soldiers are not sociopathic murderers. They are normal human beings who joined the armed forces under some idealistic notion that they were serving their country. When they kill people wrongfully, it’s not so easy to escape the psychological and emotional consequences arising from a troubled conscience.

Since soldiers are not permitted or encouraged to confront the reality of what they have actually done in Iraq — kill people as part of a wrongful invasion or occupation — and because they have to continue pretending that that they have killed Iraqis in service of America or for the good of Iraq, suicide becomes an easy way out to escape the ongoing pain of a guilty conscience.

Jacob Hornberger is founder and president of The Future of Freedom Foundation.