As Russian troops closed in on Ukraine by land, sea and air on Thursday, US, Canadian and EU leaders imposed new waves of sanctions against Moscow, citing grave concerns that left unchecked, Russian aggression threatens to upend global order.

Earlier Thursday, Russia’s Vladimir Putin ordered a so-called “special military operation” into Ukraine — essentially a declaration of war. This order came weeks after nearly 200,000 Russian troops had begun amassing along the country’s border with Ukraine, and days after Putin formally recognized the pro-Russian breakaway regions of Donetsk and Luhansk. These regions have remained under rebel control since 2014, when Ukraine’s former Kremlin-loyal leader Viktor Yanukovych was ousted amid the Maidan Revolution, ushering in an era of democratic, pro-Western rule. That same year, Russia annexed the Ukrainian region of Crimea under the auspices of a “referendum” broadly understood to have been illegitimate, but did not, at the time, opt to bring Donetsk or Luhansk into its federal fold.

In a rambling speech, Putin railed against what he sees as the undue influence of Western hegemony in international justice. He then cited as justification for the invasion Article 51 of the UN Charter, which states that members have the right — individually and collectively — to exercise self defense in the event of an armed attack, until the Security Council — the UN’s executive arm — has taken the necessary measures to maintain international peace and security.

“The purpose of this operation is to protect people who, for eight years now, have been facing humiliation and genocide perpetrated by the Kiev regime. To this end, we will seek to demilitarize and denazify Ukraine, as well as bring to trial those who perpetrated numerous bloody crimes against civilians, including against citizens of the Russian Federation.,” he said. Putin did not, in the speech attempt to explain why Article 51 should apply. Notably, the UN Security Council was meeting about the situation at the very moment Putin ordered his troops to attack. Further, while Putin and various oligarchs have mentioned “genocide” in passing, none appear to have offered any compelling evidence to substantiate these claims.

In response to what has been broadly viewed as Russian acts of aggression, the US and EU swiftly imposed new rounds of sanctions Thursday.

“What is at stake is not just Donbas, it is not just Ukraine. What is at stake is the stability of Europe and the whole international order, our peace order. President Putin chose to bring war back to Europe. In a determined and united response, the European Union will make it as difficult as possible for the Kremlin to pursue its aggressive actions,” said an EU statement Thursday. In a bid to make Russia face “massive and severe consequences,” EU leaders agreed on a package of sanctions covering the financial, energy, and transport sectors; dual-use goods; export controls and financing; and visa policy, as well as expanding the list of well-connected Russians subjected to individual sanctions.

While announcing new US sanctions, Biden said: “The scale of Putin’s aggression and the threat it poses to the international order require a resolute response, and we will continue imposing severe costs if he does not change course.” The US sanctions also target Moscow’s financial sector, severing ties between Russia’s largest bank — Sberbank — and the US financial system, and imposing full blocking sanctions against the country’s second largest bank, VTB, and other large financial institutions. The US also expanded its list of Russian elites subject to individual sanctions, among other measures. 

Canadian Prime Minister Justin Trudeau on Thursday also announced newly expanded sanctions in response to the “massive threat to security and peace around the world” imposed by Russia.

These are the latest additions to a vast body of international sanctions that have been levied against Moscow since its annexation of Crimea in 2014. In light of this, some have questioned the efficacy of a sanctions-heavy strategy against Russia, particularly in the face of military aggression.

“Relying on economic sanctions alone will not appreciably change the Kremlin’s behavior. We need new diplomatic strategies, including institutional cooperation between NATO and Russia’s Collective Security Treaty Organization,” wrote Anna Ohanyan, professor of international relations at Stonehill College, in an op-ed for the Los Angeles Times on Thursday.

Evelyn N. Farkas, who served as deputy assistant secretary of defense for Russia, Ukraine, Eurasia in the administration of former US President Barrack Obama, wrote in a Defense One op-ed last month: “The United States must do more than issue ultimatums about sanctions and economic penalties. U.S. leaders should be marshalling an international coalition of the willing, readying military forces to deter Putin and, if necessary, prepare for war.”

Russia’s ambassador to Sweden appeared to confirm these suspicions earlier this month. “Excuse my language, but we don’t give a —- about all their sanctions. We have already had so many sanctions, and in that sense they’ve had a positive effect on our economy and agriculture. . . . We are more self-sufficient and have been able to increase our exports,” Viktor Tatarintsev said, as quoted by The New Yorker.