The question of proportionality in war — whether military action causes more evil and disorder than it remedies — is an especially difficult question to answer, according to the theologians interviewed by CNA.
Said Miller: "To have the moral justification and to make some calculus of proportionality, you have to have some good intelligence about who could be harmed. Obviously, there can be unintended consequences, but you have to have a good amount of information about what the effects of a military action could be before you can judge if it is a just response."
Explained O’Neill: "Of course, so much of this is about thinking five or 10 steps down the road, and it is about balancing the need to prevent an escalation while keeping an eye on all the possible unforeseen consequences."
Some European bishops who joined the Holy Father in calling for prayer for peace in the Ukraine this week voiced concerns about escalation. Major Archbishop Sviatoslav Shevchuk, head of the Ukrainian Greek Catholic Church, and Archbishop Stanisław Gądecki, president of the Polish bishops conference, said earlier this week that rising tensions with Russia pose “a great danger” to the whole of Europe “which may destroy the progress made so far by many generations in building a peaceful order and unity in Europe.”
Ukraine, which has a population of 44 million people, borders Moldova, Romania, Hungary, Slovakia, Poland, Belarus, and Russia.
In addition to satisfying the first set of conditions simultaneously to arrive at a decision that a just cause exists, the war must also be carried out in a just way. The Vatican II document Gaudium et Spes teaches clearly that: “The mere fact that war has regrettably broken out does not mean that everything becomes licit between warring parties.”
This means that military actions must meet certain moral conditions. For instance, indiscriminate destruction of cities or civilian life is prohibited, and the basic human rights of non-combatants, wounded soldiers, and prisoners of war must not be abrogated.
But serious questions of what military actions constitute ius in bello, or just acts in war, have multiplied in recent years with the advent of drone strikes and other acts of war against infrastructure that serves dual military and civilian purposes.
Modern conflicts often involve remote means of warfare and targets which are of unclear military status, such as governmental intelligence posts, radar stations, or other logistical installations. While the personnel in them might be primarily military, the presence of civilians has to be weighed carefully in discerning military action.
"The classification of people involved can be very difficult to discern in modern conflicts," O'Neill said.
"We don't necessarily see artillery shelling enemy lines. With strikes from distance on military targets, there are people involved who might not be military personnel: they might be government intelligence workers or people in a gray area,” he said. “But then there's the possibility of just the civilian janitor in the building — how do you put them in the balance of proportionality?
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“It makes things very difficult."
O'Neill said that with modern means of warfare, there is a very high burden on governments to take all measures possible to limit the loss of potentially innocent human life.
The Russo-Ukrainian War began in February 2014, focused on the east of Ukraine. The conflict has claimed more than 14,000 lives and driven 1.3 million people from their homes, according to Caritas Internationalis, a Vatican-based confederation of Catholic charities raising funds for those affected.
The warring parties agreed to a cease-fire in July 2020. But Russia has sent an estimated 100,000 troops to the Ukrainian border. U.S. President Joe Biden said on Jan. 19 that he expected Russian President Vladimir Putin to order an invasion.
Since then, tensions have not cooled down. Kremlin spokesman Dmitry Peskov told reporters on Thursday that Putin will take time to study documents hand delivered by Western leaders regarding the conflict. But, he added, “it cannot be said that our views were taken into account, or that a readiness to take our concerns into account was demonstrated."