Mary Ellen O'Connell

Notre Dame Law School

Phone
574-631-7953
Email
MaryEllenOConnell@nd.edu
Website

Robert and Marion Short Professor of Law, Research Professor of International Dispute Resolution, Kroc Institute for International Peace Studies

  • International law
  • International legal regulation of the use of force
  • Conflict and dispute resolution

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O'Connell’s Latest News

O'Connell in the News

War by algorithm raises new moral dangers

Mary Ellen O’Connell, a law professor at the University of Notre Dame who supports a ban on LAWS, says that realists tend to favour the projection of power over the protection of the rule of law.

Top UN court will hold hearings in a case accusing Germany of facilitating Israel's Gaza conflict

“The case next week in The Hague will likely further galvanize opposition to any support for Israel,” said Mary Ellen O’Connell, a professor of law and international peace studies at the University of Notre Dame.

Top UN court orders Israel to prevent genocide in Gaza but stops short of ordering cease-fire

Now we find you are in the midst of committing genocide,’” said Mary Ellen O’Connell, a professor of law and international peace studies at Notre Dame University’s Kroc Institute.

How genocide officially became a crime and why South Africa is accusing Israel of committing it

The reason the genocide convention exists “is related directly to what the (Nazi) Third Reich attempted to do in eliminating a people, the Jewish people, not only of Germany, but of Eastern Europe, of Russia,” said Mary Ellen O’Connell, a professor of law and international peace studies at Notre Dame University’s Kroc Institute.

Analysis: Israel’s war on Hamas raises significant moral concerns as Gaza death toll soars

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.

What a Catholic peace studies expert thinks is the way out of war in Gaza

Mary Ellen O’Connell, a professor of law at the University of Notre Dame and of international peace studies at the university’s Kroc Institute, believes this tit-for-tat strategy is precisely the wrong response if regional de-escalation is indeed the desire of the Biden administration. 

Opinion: Marjorie Taylor Greene botches the explanation

Hamas’ massive, brutal attacks and kidnappings perpetrated against Israelis on October 7 violated humanity’s most fundamental international legal principles,” wrote Mary Ellen O’Connell, an international law expert at the University of Notre Dame.

Move To Update Nuclear Gravity Bomb Concerns Catholic Leaders, Peace Advocates

“We need to beef up our State Department. We need skills for diplomacy,” said Mary Ellen O’Connell, a law professor and professor of international peace studies at the University of Notre Dame’s Kroc Institute. “

Opinion: Biden needs to call for a ceasefire and restore respect for international law

Mary Ellen O’Connell is the Robert and Marion Short professor of law and professor of international peace studies-Kroc Institute at the University of Notre Dame.

Supreme Court Seems Ready to OK GOP South Carolina Map

Audio

International law expert Mary Ellen O'Connell, a professor at Notre Dame Law School, discusses the law governing international conflicts like the Israel-Hamas war. June Grasso hosts.

Michiana leaders react to Israel, Hamas war

A statement from Notre Dame law professor Mary Ellen O’Connell argues that Israel has the right to use military force defensively, but not offensively, and that it should restrict its defense to shielding communities where nationals live.

States are becoming more brazen about killing foes abroad

Mary Ellen O’Connell of the University of Notre Dame in America argues “there is no grey zone”. 

Holy See urges more nations to sign treaty banning cluster munitions

Mary Ellen O'Connell, a professor at Notre Dame Law School who specializes in international law and conflict resolution, told OSV News that "the Catholic Church is in full support of the total ban on cluster munitions" due to its effects on civilians, including long after the conflict.

U.S. to provide Ukraine cluster munitions opposed by the church as ‘inhumane’

Mary Ellen O’Connell, a professor at Notre Dame Law School who specializes in international law and conflict resolution, told OSV News Ukraine “has the legal and moral right to defend itself.”

Correio Braziliense

Primeiro incidente direto entre aeronaves da Rússia e dos EUA causa tensão diplomática

Em entrevista ao Correio, Mary Ellen O'Connell — professora de direito e especialista em resolução de disputas internacionais pela Universidade de Notre Dame (em Indiana) — admitiu que qualquer engajamento militar entre EUA e Rússia é "muito grave". 

Russian fighter jet collides with US Air Force drone over Black Sea

The U.S. should not respond with direct force against Russia, said Notre Dame Law School professor Mary Ellen O’Connell, an expert on international law and the use of force. While the drone was probably conducting surveillance for Ukraine, Russia’s disruption of the Reaper was within the laws of armed conflict, even if Russia had better ways of doing so, she said.

Russian fighter jet collides with US drone causing it to crash into Black Sea

Mary Ellen O’Connell, a Notre Dame Law School professor and expert on the international law and the use of force, noted that by dumping fuel and downing the drone, the Russian pilot was “further polluting the fragile Black Sea”, but she noted the US had not called the interception “unlawful”.

Cardinal McElroy says church must 'redesign' just-war theory, favor nonviolent action

Drawing on six decades of papal teaching on peace, the cardinal told an audience at the University of Notre Dame on March 1 that Catholics are facing a "new moment" in history, one that requires finding nonviolent alternatives to prevent war.

Southern California Public Radio

It’s Been A Year Since Russia Invaded Ukraine. Reflecting On What’s Happened Since And What’s To Come

Audio

Joining to discuss is Kateryna Malofieievafreelance journalist based in Ukraine, Daniel Treismanprofessor of political science at UCLA, Ambassador Oleh Shamskur, nonresident senior fellow at Atlantic Council and former ambassador of Ukraine to the United States from 2006 to 2010, and Mary Ellen O'Connell professor of international law at the University of Notre Dame. 

Putin's suspension of key US-Russia nuclear arms treaty increases global risk, say experts

Mary Ellen O'Connell, a professor of law and a research professor of international dispute resolution at the Kroc Institute for International Peace Studies at the University of Notre Dame, told OSV News that the suspension is different in substance than a withdrawal. Gerard Powers, director of Catholic peacebuilding studies at Notre Dame's Kroc Institute for International Peace Studies and coordinator of the Catholic Peacebuilding Network, told OSV News that "during the Cold War, arms control was often possible when there were thaws in U.S.-Soviet relations."

Indiana Landmarks

A Message to the Future

After living in Germany and historic Midwestern communities, Mary Ellen O’Connell and Pete Bauer appreciate quality craftsmanship and walkable cities. So, in 2005, when Mary Ellen accepted a teaching position at the University of Notre Dame’s law school in South Bend, the couple made finding a historic home within biking distance of the university a top priority.

Notre Dame professor on Chinese spy balloon, international law

Video

Mary Ellen O'Connell says spying is nothing new, but anyone trying to carry out intelligence must stay outside the 12-mile territorial sea boundary.

Sarajevo’s agony echoes as Ukraine braces for a dark winter

“It is absolutely the case that terrorizing the civilian population, to break their morale, to get them to demand of their leaders that they surrender, is not a form of military necessity,” said Mary Ellen O’Connell, a University of Notre Dame law professor and expert on international law.

The Intercept

Will Biden sell advanced drones to Ukraine?

Mary Ellen O’Connell, an international law professor at the University of Notre Dame, said the Pentagon’s stance on the risks to its technology is “yet another indication of U.S. foreign and security policy stuck in Cold War thinking. It’s also another example of post-Cold War disinterest in international law.” 

As Russia Threatens Captured American Vets, U.S. Invokes Laws of War

Every fighter claiming to be a legal combatant is entitled to a hearing to learn if their conduct in any way violated the law of war, such as failing to wear a uniform or some form of insignia while engaging in military operations, said Mary Ellen O’Connell, a professor of international law at the University of Notre Dame.

Russian sentenced to life in Ukraine's 1st war crimes trial

Mary Ellen O’Connell, an expert on international law at the University of Notre Dame, said that putting Shishimarin on trial could prove “extremely detrimental to Ukrainian soldiers in the hands of Russia.”

Accountability for alleged war crimes in Ukraine likely a long way off

Although inquiries are underway, Mary Ellen O’Connell, professor of law at the University of Notre Dame, called for a negotiated end to the war — the sooner the better.

War crime charges may not be enough to deter Putin — even as evidence of Russian atrocities mounts

“International condemnation or war crimes threats will have little effect on Russian behavior. This is nothing new for them,” said Bob Latiff, adjunct professor at the University of Notre Dame, citing previous offenses in Syria and Chechnya...“The crimes are increasing resolve among Ukraine’s existing supporters to continue and even step-up military assistance and economic pressure. But ending the war will require a bigger coalition of support — reaching China, India, and others,” Mary Ellen O’Connell, professor of law at the University of Notre Dame, said.

Putin acting 'irrationally,' says analyst, but settlement possible

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Mary Ellen O’Connell, Professor of International Dispute Resolution at the University of Notre Dame, said that the conflict is at a critical juncture, and that Russia’s failure to attain its military objectives provides an opportunity.

A 'cold-blooded' alliance? China could be a pivotal force in Russia's war against Ukraine

“Russia would like China to step in to mitigate sanctions,” said Notre Dame Law School professor Mary Ellen O’Connell, author of "The Crisis in Ukraine.”

Ukraine and Russia from an international law perspective with Notre Dame professor

Audio

Mary Ellen O’Connell, International Law specialist and Law and research professor at Notre Dame talks about previous conflicts with NATO countries. The two discuss Russia’s position in the United Nations and putting pressure on Putin. 

How the world can make Putin pay for invading Ukraine

Mary Ellen O’Connell is the Robert and Marion Short Professor of Law and research professor of international dispute resolution at the University of Notre Dame.

Notre Dame professor explains history of Russia-Ukraine relations

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Professor Mary O'Connell says Ukraine became a fully independent member of the United Nations under a treaty with the Soviet Union in 1991.

Has Russia already invaded Ukraine? An expert clarifies 'invasion'

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We asked Mary Ellen O'Connell, professor of international dispute studies at Notre Dame Law School and the Kroc Institute for International Peace Studies, how do we know when we've passed the red line?

EXPLAINER: Ukraine shows how not all 'invasions' are equal

Mary Ellen O’Connell, a Notre Dame law professor and an expert on international law and the use of force, says any crossing of a national border with military forces is unlawful, even if it’s called something other than an invasion.

Yemen: Saudi-led airstrike on rebel-run prison kills at least 60 and wounds 200

“News of the Saudi air strike on a prison – a protected civilian site – and knocking out Yemen’s internet is both tragic and no surprise,” said Mary Ellen O’Connell, a professor at Notre Dame law school in the US. 

Family seeks to sue Lebanon over dead father’s captivity

Mary Ellen O’Connell, a professor at the Notre Dame Law School, said it may be challenging for a case to be brought against Lebanon, which is not designated a “state sponsor of terrorism.”

Biden didn’t accept Putin’s ‘red lines’ on Ukraine – here’s what that means

“Putin has said again and again that Ukraine is culturally and historically part of Russia. Ukraine’s history is complicated, but for Putin and other Russians, Russia should by rights include Ukraine,” said Mary Ellen O’Connell, a professor at the University of Notre Dame, when asked why Russia opposed NATO’s expansion.

Biden risks killing more civilians with drone strikes in Afghanistan as part of his 'over-the-horizon' strategy, experts warn

"Not only do remote pilots have only a vague idea in most cases who they are killing, now that the war is over in Afghanistan, it will be virtually impossible to use drone strikes legally," Mary Ellen O'Connell, Notre Dame Law School professor and expert on international law in relation to the use of force, told Insider.

Politifact

COVID-19 vaccination does not violate the Nuremberg Code

The Nuremberg principles that Key alludes to are not part of U.S. law; they refer to a treaty agreed to after World War II to prosecute individuals for war crimes, and crimes against humanity, said Mary Ellen O’Connell, a law professor at the University of Notre Dame School of Law.

ABC 57

Expert: Taliban takeover inevitable, a multi-administration failure

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Despite the poorly planned exit, Mary Ellen O’Connell says this was a multi-administration failure three presidents in the making.

Xinhua

Five militiamen killed in U.S. airstrikes in Iraq, Syria

Mary Ellen O'Connell, a professor at Notre Dame Law School, has criticized the U.S. attacks as a violation of international law.

Australian Broadcasting Corporation

Planet America

Video

Mary Ellen O'Connell, law, speaks with Australian Broadcasting Corporation. (starting at 15:00)

Rockets strike Iraqi base housing US troops ahead of Pope Francis visit

Mary Ellen O’Connell, a professor of law at the University of Notre Dame and an expert on the use of military force, said in emailed comments that the attacks in Iraq "demonstrate the danger and illegality of deploying force for deterrence."

Militia official: US strike in Syria kills 1, wounds several

Mary Ellen O’Connell, a professor at Notre Dame Law School, criticized the U.S. attack as a violation of international law.

US launches air strikes against Iran-linked militias in Syria

Mary Ellen O’Connell, an expert in the lawful use of force at the University of Notre Dame, described the act as a “grave violation of international law”, saying the US had no right to target Syrian soil in reprisal for an act committed in Iraq.

First US military action under Biden draws criticism

Mary Ellen O’Connell, a professor at Notre Dame Law School, criticised the US attack as a violation of international law.

Why Democrats are blasting Biden’s attack against Iranian proxies in Syria

Mary Ellen O’Connell, a professor at Notre Dame and co-author of Self-Defense Against Non-State Actors, told me she agrees that the president should come to Congress when there is time to seek authorization.

Unpacking the fine print of Biden's declaration about the war in Yemen

I spoke about Biden's announcement on Yemen with Mary Ellen O'Connell, a professor at the University of Notre Dame Law School and a research professor of international dispute resolution at Notre Dame's Kroc Institute for International Peace Studies.

US bombs facilities in Syria used by Iran-backed militia

Mary Ellen O’Connell, a professor at Notre Dame Law School, criticized the U.S. attack as a violation of international law.