In the early hours of Oct. 7, Hamas – defined by the U.S. State Department as a foreign terrorist organization – launched a barrage of 3,000 missiles from the Gaza Strip against the state of Israel, combined with ground attacks upon civilians and soldiers alike.

The resulting one-day death toll of 1,200 people in Israel represented the largest Jewish loss of life since the Holocaust.

As The Times of Israel observed two days later, “There have been bloody days in Israel’s history and for Jews around the world since 1945, but none has had a civilian death toll this high. Israeli wars have had higher casualty totals overall, but none has seen this many civilians murdered in a single day.”

Global reaction was swift and widespread, with leaders of democratized nations simultaneously condemning Hamas while asserting Israel’s right to defend itself.

That narrative, however, has shifted slightly with the recent release of a U.S. intelligence assessment indicating almost half the munitions Israel has used in Gaza since the war began are “dumb bombs” – unguided weapons lacking the targeted precision of more advanced armaments, which also may inflict greater civilian casualties.

With more than 22,100 deaths and 57,000 injured as reported by Jan. 2 by Gaza’s Ministry of Health, the question is being asked: Can Israel’s conflict conduct be considered a “just war” under the Catholic understanding of the concept?

Mary Ellen O’Connell, a professor of law and international peace studies at the University of Notre Dame in Indiana, told OSV News that’s the wrong question.

“There may be one side in an armed conflict that has the legal right, and therefore the moral right, to defend itself,” O’Connell said. “But there’s no such thing as a just war; there’s no such thing as a lawful war.”

O’Connell echoed Pope Francis’s remarks during a 2022 video conference with Patriarch Kirill of Moscow, when Pope Francis declared, “There was a time, even in our Churches, when people spoke of a holy war or a just war. Today we cannot speak in this manner. A Christian awareness of the importance of peace has developed. Wars are always unjust.”

“It’s always been a misinterpretation of the concept to say, ‘This is a just war,’” O’Connell noted. “All we’re really saying is that, in certain cases, a state has a just cause to resort to an otherwise immoral action – which is the mass killing of war. You can have a just cause – but war itself is always a moral evil.”

The Catechism of the Catholic Church defines “legitimate defense by military force” using several criteria, including “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”; and “the use of arms must not produce evils and disorders graver than the evil to be eliminated.”

The catechism adds, “The power of modern means of destruction weighs very heavily in evaluating this condition.”

Israel’s present strategy, O’Connell warned, may only produce more chaos.

“Every attack that Israel undertakes is only encouraging more and future terrorist attacks on Israel,” she said. “Hamas’s popularity has gone up.”

The Palestinian Center for Policy and Survey Research reported that almost three-quarters (72 percent) of its 1,200-plus respondents in a recent survey believe Hamas’s decision to attack Israel on Oct. 7 was “correct.” Less than a quarter said it was “incorrect.”

“The goal of eliminating Hamas is first impossible; you cannot eliminate every member of Hamas,” suggested O’Connell. “And there’s no connection between that goal and what international law says Israel has the right to do.”

Gerald Schlabach, theology professor emeritus and former chair of the Department of Justice and Peace Studies and the University of St. Thomas in St. Paul, Minnesota, observed, “You have to start by saying in the Catholic understanding of just war, if you can’t discriminate between civilians and combatants – and you just attack indiscriminately – there’s no way that can meet the criteria of just war.”

That said, Schlabach told OSV News, “I think we idealize that somehow in the past there was ‘cleaner’ warfare. There’s always been a mixing of populations with military.”

Reuters noted in a report, “Rights groups and researchers say the high civilian toll arises from heavy weapons used – including so-called ‘bunker buster’ bombs aimed at destroying Hamas’s strategic tunnel network – and strikes on residential districts where Israel says Hamas has hidden militant bases, rocket launch pads and weaponry within and under apartment blocks and hospitals.”

Gaza’s health authorities do not distinguish between civilians and combatants in reporting Palestinian casualties – however, they have noted that two-thirds of the deaths in Gaza are women and children.

Hamas’s practice of using civilians as “human shields” has also been widely denounced. In November, the European Union’s chief diplomat, Josep Borrell, said, “The E.U. condemns the use of hospitals and civilians as human shields by Hamas.”

In a Dec. 14 interview with CNN’s Anderson Cooper, retired U.S. Army Gen. Wesley Clark noted his disbelief “that the Israelis aren’t doing everything that they can do, commensurate with their interpretation of their mission, to reduce these civilian casualties. ... But they’ve said they’re going to eliminate Hamas.”

After nearly three months of fighting, 80 percent of Gaza’s population, or 1.8 million people, are displaced within the narrow coastal enclave where 60 percent of the buildings (among them Catholic and other Christian facilities) are destroyed.

The U.N. has bluntly warned that hunger is everywhere in Gaza and “half of Gaza’s population is starving.”

“Even putatively just wars sow the seeds for the next war,” Schlabach said. “Even when it looks like you have just war, you’re not stopping the vicious cycle. How do you even calculate proportionality? ... Nobody’s ever defined how much collateral damage is possible.”

“In any war – even if one is only acting against legitimate targets – there are always noncombatant deaths,” said V. Bradley Lewis, associate professor in the School of Philosophy at The Catholic University of America. “You’re talking about very dangerous, lethal weapons – so that’s always the case.”

Israel’s original intention for counter attacking Hamas – its “jus ad bellum” or the conditions under which states resort to war – was “to eliminate the terrorist organization Hamas, that poses a continuing threat to Israel,” Lewis noted.

“It’s not just revenge; it’s not just about Oct. 7 – although that was the immediate cause – it’s about all the damage that Hamas could do in the future,” Lewis said. “Of course, they’ve (Hamas leaders) said they would do it all again tomorrow if they could.”

Proportionality – a “jus in bello” concern among the moral guidelines for conducting legitimate defense once war begins – has nonetheless become a concern, Lewis indicated.

However, “it’s not always easy to make an immediate judgment about that,” he noted, “in particular, because it all depends on the military value of targets balanced against what you expect to be the damage done to non-combatants; and even in some ways, to the infrastructure that’s required for civilians to live.”

Rules of engagement – typically involving military lawyers – can govern such decisions, Lewis said.

“The people who are primarily responsible for applying the just war criteria are the military and civilian decision makers, who have all that information,” emphasized Lewis. “Obviously the loss of life among civilians is always terrible – it’s one of the reasons you don’t want to fight wars.”

Israel’s military in December acknowledged that soldiers violated its rules of engagement by killing three shirtless Israeli hostages who were holding up a white flag and calling for help. The Dec. 15 incident, along with an Israeli military sniper killing two women in a Catholic parish complex Dec. 16, an act which prompted papal outrage, has added to growing widespread concerns about Israeli troops’ conduct in combat.

U.S. Secretary of Defense Lloyd Austin – following daylong Dec. 18 meetings in Tel Aviv – emphasized that “protecting Palestinian civilians in Gaza is both a moral duty and a strategic imperative.”

President Joe Biden has twice authorized emergency weapons sales to Israel – $254 million in total in December – bypassing Congress’ ability to evaluate, approve or block the transfers or set conditions.

Despite Biden’s “rock solid and unwavering support” for Israel, the president’s call for a revitalized Palestinian Authority to take post-war control of Gaza was rebuked by Israeli Prime Minister Benjamin Netanyahu. Biden, in turn, warned Israel’s “indiscriminate bombing” was starting to cost it global support.

The administration is also expressing growing unease at calls from some Israeli political leaders, both within and without the Israeli government, to eliminate Hamas by rendering Gaza completely uninhabitable, requiring the resettlement of Palestinians to a third country.

State Department spokesperson Matthew Miller called such calls “inflammatory and irresponsible” and “should stop immediately.”

“We have been clear, consistent, and unequivocal that Gaza is Palestinian land and will remain Palestinian land, with Hamas no longer in control of its future and with no terror groups able to threaten Israel,” he said. “That is the future we seek, in the interests of Israelis and Palestinians, the surrounding region, and the world.”