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CNN reporter: This shows just how close Russian forces are to Ukraine capital
02:41 - Source: CNN

Editor’s Note: 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. She is the author of “The Crisis in Ukraine,” editor of the book, “What is War?” and previously served as a professional military educator for the US Department of Defense. The opinions expressed in this commentary are her own. View more opinion at CNN.

CNN  — 

Russian President Vladimir Putin’s full-scale invasion of Ukraine in the pre-dawn hours on Thursday is the most serious violation of international law since Iraq invaded Kuwait in 1990. It is also the most serious violation in Europe since World War II. These are the only cases where one state has attempted to absorb, and, thus, eliminate a fully sovereign state member of the United Nations since the organization was founded in 1945.

Germany violated the most basic rule of international law then. Russia is violating the same law now: the prohibition on the use of force codified in United Nations Charter Article 2(4).

The charter provides for only two exceptions: Force authorized by the UN Security Council and force in self-defense if an armed attack occurs.

Russia has no justification under either of these exceptions for the lawful use of force against another nation; its recognition of two Ukrainian regions – Donetsk and Luhansk – as independent states does not change this fact. In 2014, Russia tried much the same excuse. It recognized Crimea as independent just before purporting to “annex” the Ukrainian peninsula. The annexation was no more than an act of aggression, and aggression does not change borders – the only thing that does is the willing consent of the state that stands to lose territory.

Ukraine has the right to fight and other states may join it in collective self-defense. The US has ruled out such military assistance as of now. It is obligated only to fight to defend members of the North Atlantic Treaty Organization under Article 5 of the NATO treaty. Should Putin be so foolhardy as to go further with his aggression, an attack on one NATO member would be treated as an attack on all.

Unfortunately for Ukraine, the NATO treaty does not apply to Ukraine, since it is not a member state. And while the UN Security Council could mandate fighting for Ukraine, that will likely not happen. The 15-member UN Security Council was established to enforce Article 2(4). It operated as designed when Iraq invaded Kuwait. The Council ordered global sanctions. When those did not work, it authorized a counter-invasion force under US leadership that quickly defeated Iraq’s military. The Soviet Union joined in a series of unanimous Security Council resolutions upholding the independence of Kuwait and the grave violation of the Charter constituted by a cross-border invasion aimed at conquest.

The Council should now do the same for Ukraine, but Russia has replaced the Soviet Union as a permanent member of the Council. It can veto resolutions demanding an end to its aggression against Ukraine. If Russia were to do this, the UN General Assembly – the body that includes all 193 member states – could activate the Uniting for Peace Resolution and meet in an Emergency Special Session to coordinate worldwide sanctions and other measures to enforce the Charter.

The General Assembly first acted under Uniting for Peace in 1956, sending a UN peacekeeping force to the Middle East to end the Suez Canal Crisis. The crisis erupted when Britain, France and Israel violently intervened against Egypt.

The General Assembly can demonstrate to Russia in the current crisis how isolated it is and launch a global campaign of sanctions. But this may not be enough; Ukraine also needs support – funds and refuge for its population who are fleeing. Its government should be offered a safe haven to continue to operate in opposition to Russia’s aggression.

Even if the UN fails to act, states have a clear legal duty to support Ukraine and the rules-based order founded on the prohibition of force. It’s time to cut financial, trade and commercial ties with Russia; it’s time to cut oil and gas purchases. While Germany has already stepped up by postponing the gas pipeline Nord Stream 2, all states need to do more. Cutting fossil fuel purchases has not even been on the table. The New York Times reported Wednesday that “no Western officials have even proposed choking the lifeblood of Russia’s economy by cutting off its lucrative energy exports. Experts say that a move against Russian Energy revenues would have the biggest impact, but that it would also lead to a precarious political situation for Mr. Biden and other world leaders…”

Now is the time for world leaders to lead. They need to explain to their citizens that paying more for fuel or even forgoing purchases is a small price to pay in support of Ukraine and the rule of law – not to mention the climate. We did so much more for Kuwait.

Caution is, however, required. Some sanctions could cause more harm than good and are, therefore, unlawful. Cyberattacks are a case in point. Targeted attacks on military communications in response to Russia’s invasion are acceptable offensive actions in cyberspace during armed conflict. Other malicious cyber conduct could result in illegal disruptions beyond the control of operators.

Now and until the crisis is over, international negotiators need to press home the advantage of a united world imposing financial hardship on Russia. There is a basis for a long-term peace settlement in the 2015 Minsk II agreement, which included provisions for a ceasefire, disarmament and eventually autonomy for Luhansk and Donetsk under Ukrainian sovereignty. France, Germany, and China have been pressing for renewing the process that led to Minsk.

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    That is the right thing to do, but now the goal of that process must be more generous for Ukraine. While Russia has legitimate concerns for its security, it must respect Ukraine’s entire territory and independence. It needs to leave Ukraine. UN peacekeepers can replace Russian troops in Eastern Ukraine to support a ceasefire and disarmament with the assistance of monitors from the Organization for Security and Cooperation in Europe. Redress for broken treaties relevant to Russia’s security can be found.

    The way forward for Ukraine and the international community begins with Russian compliance with the prohibition on force – an imperative norm binding all states.