The White House’s lack of credibility on war in Iraq is both inherited and created anew.
“The first mistake was going into Iraq, the second was getting out,” observed Catholic writer Russell Shaw.

“The first of these blunders was George Bush’s in launching an unjust and unnecessary war. The second was Barack Obama’s in pulling out before authentic stability had been restored in a country the U.S. had done so much to destabilize,” wrote Shaw last week in a Catholic News Agency column. “By now we’ve paid heavily for both mistakes.”

While Protestant clergy are mostly mute about the U.S. military role in the unfolding, brutal civil war in Iraq, Catholic leaders are not.

In a letter to White House’s National Security Advisor, Bishop Richard Pates of Des Moines called for diplomatic efforts and humanitarian assistance, noting the failure of the Iraqi government to seek an ethnically and religiously inclusive government.

Pates, chairman of the United States Conference of Catholic Bishops’ Committee on International Justice and Peace, wrote as President Obama announced that 300 American advisers were being sent to Iraq.

Within a week, he was seeking $500 million for the so-called “moderate” Syrian opposition, sending Hellfire missiles to Iraq’s military and flying U.S. drones over the embattled country.

How should Christians think morally about the expanding U.S. war in Iraq?

Having spent $1.7 trillion in war costs in Iraq between the 2003 invasion and the end of fiscal year 2014, not counting the long-term veteran care, is it right to go into this war?

One way to explore that question is to look at the time-honored rules of Just War, a moral tool for critiquing government war-making arguments.

Reviewing these rules gives Christians a nonpartisan way to engage in discernment.

Here are the rules:

1. Just Cause. Protecting innocent human life is a just cause. Stopping genocide is a just cause for war. U.S. military intervention in Rwanda to halt genocide would have been a moral use of force, for example.

Does using military force in a civil war to prop up the divisive, corrupt Iraq government qualify as a just cause?

2. Just Authority. Presidents need congressional authority to make war. Washington has kicked around the question of whether Obama needs congressional authority. Some Democratic leaders say he does. Others disagree, supporting unilateral action. A similar dynamic exists among Republicans.

3. Last Resort. Nations must exhaust efforts at resolving a conflict before launching into war.

Has the U.S. made meaningful, prolonged efforts at seeking resolution with the Islamic State in Iraq and Syria (ISIS)? Is the Obama administration doing what is needed to seek a just, inclusive government in Baghdad? Did it sit on the sideline for too long?

4. Just Intent. Protecting oil fields—and hence the global economy—is a wrongful reason for war. Stopping terrorism would be a just intent if it had a probability of genuine success.

5. Probability of Success. A just war must have a high chance to achieve its stated purpose. At this point, it would appear that the nation lacks a stated purpose in Iraq. If it is to end terrorism, that sounds hollow. If it is to end a civil war, that appears unrealistic.

6. Proportionality of Cost. For a war to be just, the war must do more good than harm. Do U.S. troops in Iraq and air strikes prolong the civil war, create more refugees and trigger more attacks on the Christian community in the region?

7. Just Means. Targeting noncombatant civilians is immoral. If noncombatant civilians are killed unintentionally, that is morally tolerable. That is what is called the double effect. Targeting urban areas in the midst of a civil war makes U.S. strikes against ISIS problematic.

8. Clear Announcement. Reasons for war and reconciliation must be spelled out clearly. The U.S. must state clearly why and when ISIS will be struck. And what ISIS can do to avoid being attacked.

These are high moral hurdles to cross. Yet better to cross them than to go helter-skelter back into the Iraq war—war is always more costly with more negative unforeseen consequences than projected by government leaders, profiteers and pundits.

By using the rules of Just War, Christian leaders have the resources to think morally. They have the tools to offer an alternative witness to culture, something that is clearly missing in the public square.

Robert Parham is executive editor of EthicsDaily.com and executive director of its parent organization, the Baptist Center for Ethics. Follow him on Twitter at RobertParham1 and friend him on Facebook.