Russian President Vladimir PoutineVladimir Vladimirovich PutinKennedy Center lights up blue and yellow to show support for Ukraine Russian opera star drops out of met performance to avoid Putin’s rebuke DHS grants temporary immigration status to all Ukrainians in United States MORE has a history of manipulating international law and institutions to further its imperial ambitions and disrupt the post-World War II order. After the failures to stop him in Georgia and Crimea, Putin underestimated their power and resilience. His brazen violation of the most basic rule against aggressive war backfired. Today, the post-war international order is stronger than ever, and international law will hold Putin to account.

Law has been a plaything for Putin since he studied it in St. Petersburg during the Soviet era. In 2008 he sent Russian troops to Georgia, claim the legal right of self-defense in response to non-existent Georgian aggression. He justified his 2014 annexation of Crimea on a twisted version of the international law rule of self-determination – the same rule that gave Kosovo, East Timor and South Sudan their independence. His current conquest bends the law yet again. He recognized the breakaway Ukrainian regions of Luhansk and Donetsk as independent nations and entered into “treaties” with their self-proclaimed leaders, to manufacture an “invitation” for Russian troops to enter Ukraine. He was well on his way to breaking the international system.

However, the invasion of Ukraine turns out to be the step too far the international community needed to revive international order and hold Putin to account. Precisely because of Putin’s blatant violation, the world emerged united behind the Charter of the United Nations. Russia is surrounded. The sanctions package is the broadest and most robust in history, cutting off Russia from the international banking system, breaking up the rouble, banning the import of crucial technologies, freezing the assets of Putin and his allies, blocking the Russia’s use of European Union (EU) airspace and the closing of the Bosphorus.

These sanctions are possible because of Putin’s disregard for international law. Politically, the severity of its violation has fundamentally transformed countries, like Germany, which last month shunned foreign policy activism but this week sent arms in Kyiv. Legally, Putin’s breach allows countries to take countermeasures against Russia that would otherwise be illegal – from denying Russia’s use of airspace to cutting it off from the SWIFT financial clearing system.

Last month, the post-war international order seemed to be deteriorating in the face of internal discord and a new Sino-Russian alliance autocracies. Today, however, it is this new alliance – not the Western international order – that appears to be under threat. China’s Xi Jinping was caught off guard by global unanimity, unable to condemn or tolerate Putin. While the post-WWII order may have cracked, Putin unwittingly breathed new life into it.

The resilience of the international order so evident this week gives international law the power to hold Putin accountable. The invasion of Russia is disputed before the International Court of Justice. Enterprising lawyers at the Ukrainian Ministry of Justice filed a complaint this week in The Hague, arguing that Russia violated the Genocide Convention by wrongly invoking genocide in Ukraine as a pretext for war. Although the court is moving slowly, it will likely issue Preliminary measures in favor of Ukraine.

Putin may well find himself personally prosecuted before the International Criminal Court. The tribunal, established in 2002, makes sure that the “most serious crimes of concern to the international community… do not go unpunished”. While Russia never joined, Ukraine accepted his special jurisdiction, subjecting Putin – even as President of Russia – to prosecution for crimes in Ukraine ICC Prosecutor has decided to open an investigation into new evidence of Russian war crimes, including the use of cluster munitions and the targeting of civilians.

Foreign investors in Russia and Ukraine may be able to seek financial compensation through international investment law. the 1988 Russia-Ukraine Bilateral Investment Treaty opens the door to liability of up to billions of dollars. Ukrainian investors, including Ukraine’s state-owned energy company and a Crimean-based bank, have brought such actions in connection with the annexation of Crimea. Many more could follow, subjecting Russia to billions of dollars in damages.

As a legal consequence of the invasion, Russia will find itself excluded or expelled from critical economic and security institutions. In 2014, Putin’s political crackdown led the G-8 to disinvite Russia, thus transforming itself into a more effective G-7. This offered a precedent for moves this week by the Organization for Economic Cooperation and Development and the Council of Europe get Russia out. In the coming weeks, the UN Human Rights Council – of which Russia is clumsily a member – could call for his expulsion. The UN General Assembly, which is not subject to Russia’s veto, will likely pass a condemnatory resolution, further isolating Russia. With Russia’s seat on the Security Council enshrined in the UN Charter, could its invasion present the international constitutional moment needed for Security Council reform that excludes Russia?

By abusing international law, Putin tried to break the international system. The global collective rejection of Putin’s invasion of Ukraine actually strengthened this system, unifying it in a shared commitment to sovereignty, rights and law. Putin unwittingly gave the international order exactly what it needed to hold it to account.

William Burke-White is a professor of law at the University of Pennsylvania Law School, a nonresident senior fellow at the Brookings Institution, and a member of the U.S. Department of State Secretary’s Policy Planning Staff from 2009 to 2011.