The recent events involving yet another U.S. military action abroad makes it incumbent upon us to evaluate this latest attack on Syria in light of the Just War Doctrine, which has been developed by the Catholic Church to assess the moral legitimacy of a nation’s use of its armed forces. The Catechism lays it out this way:
“The strict conditions for legitimate defense by military force require rigorous consideration. The gravity of such a decision makes it subject to rigorous conditions of moral legitimacy. At one and the same time:
“— the damage inflicted by the aggressor on the nation or community of nations must be lasting, grave, and certain;
“— all other means of putting an end to it must have been shown to be impractical or ineffective;
“— there must be serious prospects of success;
“— the use of arms must not produce evils and disorders graver than the evil to be eliminated. The power of modern means of destruction weighs very heavily in evaluating this condition.
“These are the traditional elements enumerated in what is called the ‘just war’ doctrine.
“The evaluation of these conditions for moral legitimacy belongs to the prudential judgment of those who have responsibility for the common good.” (Catechism of the Catholic Church, §2309) 
It is important to remember that all four of the conditions must be met in order for a military action to be morally justifiable. It is insufficient if only three, two, or one of the conditions are satisfied. Let’s take a look at the American attack on Syria and see if it was in compliance with the Just War Doctrine, taking each of the four conditions in order.
The first condition is that “the damage inflicted by the aggressor on the nation or community of nations must be lasting, grave, and certain….” But Syria hasn’t been inflicting any damage, or threatening to inflict any damage on the United States, so the U.S. cannot claim that it is defending itself from harm. Moreover, the government of Bashar al-Assad is inflicting harm only within the borders of Syria, which would indicate that it is not inflicting damage on the family of nations.
Some will object that the refugees coming out of Syria have caused an economic drain on the family of nations, so that an attack on Syria can be justified on that ground. But in order to satisfy the first condition the damage must be of sufficient gravity. We should think of destruction of cities and loss of life in this connection. Causing a need of humanitarian aid simply isn’t serious enough. Otherwise a country’s causing us expenditure by its policies would be a legitimate basis for waging war against it, which would hardly be a rational approach to international conflict.
If the Syrian government is indeed using chemical weapons on its own citizens after being warned repeatedly not to do so, and after assurances were made that it was no longer in possession of such weapons, then it must be acknowledged that further negotiations are not likely to be fruitful. Bashar al-Assad is going to do what he wants to do, and continuing to jawbone about it isn’t going to be effective. This condition, then, by itself, would justify the American attack. But, again, all of the conditions must be met in order to satisfy the Just War Doctrine.
The third condition is that “there must be serious prospects of success….” Now while the presence of the Russians in Syria provided more of a challenge than would be the case otherwise, there was no real likelihood that the American armed forces would be unable to accomplish its limited mission. The Russians may have threatened to intercept the American missiles, but Vladimir Putin is not irrational, and engaging the United States military and starting World War III was not seriously to be anticipated. So there was sufficient likelihood of the mission’s success to satisfy the third condition.
The fourth condition is that “the use of arms must not produce evils and disorders graver than the evil to be eliminated, with the proviso that the “power of modern means of destruction weighs very heavily in evaluating this condition.” There was some concern expressed before the attack that a nuclear war could be sparked due to the presence of the Russians in Syria. But although an attack on Russia itself would certainly intensify the likelihood of nuclear war, there wasn’t any real likelihood that a non-nuclear attack on a Russian ally was going to provoke such a response. The Russians are as aware as the Americans that a nuclear war would have no winners.
It appears, then, that three out of the four Just War conditions point to the legitimacy of the attack. But, of course, that is not enough. Syria does not present a threat to either the United States individually, or to the body of nations as a whole sufficient to have justified the American military action.
In the next installment, barring some dramatic occurrence, we’ll take a look at the just war criteria of St. Thomas Aquinas, and their application to the American attack on Syria.
The icon of St. Joseph the Worker is by Daniel Nichols.