International norms make it obsolete – unpredictability against great power actors creates uncertainty of retaliation.

Today, when we talk about global order, we often lament the divisions inside the United Nations Security Council. This year marks the 50th anniversary of important unity: when the U.N. Security Council unanimously recommended German membership in the United Nations. The German Democratic Republic and the Federal Republic of Germany both entered the U.N. in September 1973.

Germany today is the U.N.’s fourth-largest financial contributor and has been elected to six different Security Council rotations. Germany, along with Namibia, is currently facilitating consultations for the U.N.’s 2024 “Summit of the Future,” to consider how the multilateral system should address old and new challenges.

My own career had two primary chapters: as a U.S. diplomat, mostly serving overseas, and then as the U.N. under-secretary-general for political affairs. Those two jobs put me in touch with different types of folks.

I will draw from both of those experiences in discussing the impact of the war on Ukraine in four areas:

First, an overview of the existing multilateral system and why Russia’s invasion of Ukraine is almost unprecedented in its breach of the “rules of the road” that have guided post-World War II interstate relations.

Second, for comparison, two examples from the 20th century of how the U.N. responded to earlier challenges to peace and security.

Third, my analysis of how the U.N. has reacted to Russia’s invasion of Ukraine (spoiler alert: so far, the U.N. response to the challenges created by that invasion has been better than I anticipated, despite our collective failure to prevent war).

Fourth, how we should think about the future of the U.N. and the multilateral system more generally, in light of the war on Ukraine? Russia’s invasion creates new challenges and exacerbates existing concerns about the global order.

First, the existing multilateral system. The multilateral system, or the global order, rests on a number of overlapping and intersecting mechanisms that work in tandem. We’ve inherited most of these from the post-World War II and Cold War periods: the U.N. with peace and security at its heart; the International Monetary Fund and World Bank; NATO; the European integration project that became the European Union; the World Trade Organization that evolved from the General Agreement on Tariffs and Trade; the Helsinki process that eventually became the Organization for Security and Cooperation in Europe (OSCE); and others.

These institutions, treaties, and alliances have different purposes and governing structures, along with distinct yet often overlapping memberships. Some, like the U.N., have enormous bureaucratic reach. Others, like the Group of Seven, have no permanent secretariat. Their legal statuses vary considerably. But together, these comprise the so-called rules-based international order. “Guidelines” is probably a more accurate description than “rules,” as states choose voluntarily to sign up, out of recognition of reciprocal benefit.

Even if not always followed, these guidelines are more or less universally accepted as legitimate. In increasing predictability, they reduce risks for all. And the system has been sufficiently flexible to endure through three distinct geopolitical phases: the Cold War, the immediate post-Cold War years when the United States dominated the agenda, and the emerging more multipolar environment of today.

We all know examples where this international order has failed — Srebrenica and Rwanda, to name two notorious examples. But the system has succeeded at its most fundamental level: there has been no World War III. That is not nothing. Indeed, that was the primary objective in 1945 of the key architects of the international system.

But is that sufficient? Even before February 24, issues such as economic inequality, the climate crisis, and the pandemic prompted nagging questions about how effective institutions created in a different geopolitical climate are in today’s world. Russia’s war has hyper-charged that debate.

Shivshankar Menon, India’s former national security advisor, argued recently in Foreign Affairs that the war in Ukraine is seen by many to be about the future of Europe, not the future of the world order. Indian Foreign Minister Subrahmanyam Jaishankar went further, claiming that Europe thinks its problems are the world’s problems, but that the world’s problems are not considered to be Europe’s problems.

These are thought-provoking charges. And it is indisputable that Russia’s war unhelpfully distracts us from urgent problems elsewhere. But let’s not understate the impact of Russia’s invasion. Russia dropped a barrel bomb on the fundamental principle of the international system: respect for sovereignty and territorial integrity.

To quote the preamble of the charter, the U.N. aims to “save succeeding generations from the scourge of war.” Whatever else it may do, the irreducible purpose of the U.N. is peace and security.

Article 2 of the charter offers clarity: “All Members shall settle their international disputes by peaceful means … All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state.”

Unlike murky diplomatic language, including things I’ve drafted in my career, this is unambiguous. And this is key to the entire international order.

Russia’s invasion of Ukraine is not the first violation of the charter, but it’s a particularly egregious example. Since World War II, there have been very few examples of states attempting to steal territory and change borders by force. Contrast that with the frequency of wars of territorial conquest before 1945. How many times did the frontiers in Central and Eastern Europe shift because of wars prior to 1945? The 2003 U.S.-U.K.-led invasion of Iraq made a mockery of international law, with an estimated 200,000 Iraqi civilians slaughtered in the civil strife and terrorism unleashed by the war. But the intention was never to erase Iraq from the map. Washington and London did not cite history to annex Iraqi territory. Countries have overwhelmingly accepted that respect for sovereignty and territorial integrity is at the heart of today’s multilateral system. The U.N. Charter signaled that the era of imperial conquest had ended.

Article 51 of the U.N. Charter does permit the use of force for self-defense. But Ukraine in February 2022 posed no military threat to the Russian Federation. As for NATO, U.S. forces stationed in Europe prior to Russia’s invasion were one-seventh their size compared to their Cold War presence.

Martin Kimani, Kenya’s ambassador to the United Nations, gave an African perspective from his Security Council seat:

“Today, across the border of every single African country, live our countrymen with whom we share deep historical, cultural, and linguistic bonds. At independence, had we chosen to pursue states on the basis of ethnic, racial, or religious homogeneity, we would still be waging bloody wars these many decades later. Instead, we agreed that we would settle for the borders that we inherited, but we would still pursue continental political, economic, and legal integration. Rather than form nations that looked ever backward into history with a dangerous nostalgia, we chose to look forward to a greatness none of our many nations and peoples had ever known. We chose to follow the rules of the Organisation of African Unity and the United Nations charter, not because our borders satisfied us, but because we wanted something greater, forged in peace.”

Let’s now consider two earlier U.N. reactions to threats to international peace and security.

First, the Cuban missile crisis of October 1962, when the world came alarmingly close to direct superpower war and possible nuclear Armageddon.

Much of the story is well-known. But the role of the United Nations is largely overlooked, at least in the United States. Throughout the crisis, U Thant was acting U.N. secretary-general — Secretary-General Dag Hammarskjöld had been killed in a plane crash in 1961, as he tried to bring peace to the Congo. U Thant was in direct communication with U.S. President John Kennedy and Soviet leader Nikita Khrushchev and their advisors.

Exchanging letters and calls, adjusting proposals based on the U.S. and Soviet reactions, U Thant personally brokered the face-saving trade-off — suspending U.S. invasion plans in return for the removal of Russian missiles from Cuba and (as we found out later) U.S. missiles from Turkey. U Thant went to Cuba to mollify Fidel Castro — this was not the first or last time that great powers worked behind the backs of affected clients. The U.N. verified the withdrawal of the missiles. The world exhaled.

This was preventive diplomacy at its best, averting superpower conflict and possible escalation to a disastrous nuclear showdown.

To close the file, the United States and the Soviet Union submitted a joint letter to U Thant expressing appreciation for his “efforts in assisting our Governments to avert the serious threat to the peace which recently arose in the Caribbean area.” (Fun fact: the negotiators tasked with coming up with agreed text were, for the Americans, John J. McCloy — former U.S. high commissioner for occupied Germany — and, for the Soviets, Vasily Vasilyevich Kuznetsov, then first deputy foreign minister. Kuznetsov, in a quirk of history, later became, on three different and brief occasions, the head of state in the Soviet Union’s dying days: he became acting chair of the presidium of the Supreme Soviet after the deaths of Leonid Brezhnev, then Yuri Andropov, then again Konstantin Chernenko.)

The point is the critical, effective role that U Thant played in the most significant threat to international peace and security since World War II. (Later, the U.S. relationship with U Thant cooled considerably. U Thant criticized the U.S. war in Vietnam and Israel’s occupation of the West Bank and Gaza Strip. This may explain American amnesia about U Thant’s 1962 peacemaking.)

My second example is the U.N.’s reaction to Saddam Hussein’s August 1990 invasion of Kuwait. In this case, the action moves from the U.N. Secretariat to the U.N. member states.

In speeches leading up to the invasion, Saddam rejected the very concept of Kuwait’s independence, citing shared history and culture. After seizing Kuwait by force, he initially, and briefly, set up a puppet regime before announcing the annexation of Kuwait as Iraq’s 19th province.

The Security Council immediately demanded withdrawal, imposed sanctions, and declared Iraq’s annexation of Kuwait null and void. In November 1990, the Security Council authorized force to liberate Kuwait, should Iraq not withdraw by January. In April 1991, the council mandated that shares of Iraqi oil revenues would be used to pay reparations to Kuwait. Thirteen Iraq-related resolutions between August 1990 and April 1991 alone, all defending the territorial integrity of a U.N. member state. The Russian Federation voted in favor of all of them.

After Kuwait’s liberation, the U.N. assumed the task of delineating and verifying the international border and overseeing the reparations payments.

As in the Cuban missile crisis, the U.N. acted effectively to a threat to international peace and security.

That brings me to the third point: evaluating the effectiveness of the U.N.’s response to the war on Ukraine, especially in light of the previous examples cited.

As we remember, Washington in late 2021 began sharing intelligence about the Kremlin’s invasion plans. Skepticism was understandable as citing distorted intelligence as a pretext to invade Iraq in 2003 had damaged American credibility. Leaders questioned whether Russia would really violate the most fundamental understanding of the global order that Moscow itself had helped establish in 1945. But the U.N. could have checked the warnings of Russian troop deployments via commercial satellite imagery, as the media did. Whatever he might have been doing discretely, I wish that U.N. Secretary-General António Guterres had — before the invasion — briefed the Security Council, using the drama of Article 99 of the U.N. Charter allowing the secretary-general to bring to the council’s attention “any matter which in his opinion may threaten the maintenance of international peace and security.” Guterres could have demanded an explanation from the Russian Federation about the troops positioned at Ukraine’s doorstep. He might have used his council presentation to remind all member states of their obligations to settle disputes peacefully. He might have traveled to Moscow to offer his good offices.

On the one hand, none of that would have been likely to prevent the Russian invasion. But the U.N. would have been caught trying. Even when member states behave badly, the secretary-general should have a responsibility to represent the principles of the charter.

Yet, on the other hand, had someone asked me a year ago to predict the U.N.’s impact on Russia’s invasion, I would have been dead wrong. I would have assumed that such a breach of international norms by a major power would propel the U.N. into utter irrelevance, like the League of Nations in the 1930s. After Japan’s invasion of Manchuria, Italy’s attacks on Ethiopia, and Nazi Germany’s rise, the league ceased to matter. That has not happened to the U.N. today. There is more resilience in this 78-year-old institution than many suspected.

Yes, the Security Council is gridlocked on Ukraine. But the council has continued other work: renewing and updating mandates of peace operations and adopting in December a landmark resolution exempting humanitarian deliveries from U.N. sanctions. Russia’s invasion may have exacerbated the council’s differences on contentious issues such as how to address the threat of North Korea’s nuclear and weapons programs — but it did not create them.

Action regarding the war itself shifted to the General Assembly, which voted 141 out of 193 to condemn Russia’s invasion. The assembly later rejected Russia’s annexation announcement by 143 out of 193 votes, or about 75% of the membership.