You can quantify the death and destruction wrought by Vladimir Putin¡¯s 2022 invasion of Ukraine in many ways: Tens of thousands of Ukrainians have died, including countless innocent civilians; rebuilding the country will cost at least $486 billion, according to a now-outdated estimate from the World Bank; Russia has suffered an estimated 648,000 casualties, killed and wounded.

What¡¯s harder to measure is the impact of the extraordinary economic counterattack launched by Ukraine¡¯s allies. Never before has a country as large or as integrated in the global financial system been targeted by an international sanctions coalition, one that represents half of the world¡¯s gross domestic product. It was in essence a grand experiment in economic warfare, one that¡¯s still playing out as Ukrainians try to defend their country against a relentless Russian assault.

When I was writing my book, ¡°Punishing Putin,¡± about the global economic war, a lot of people told me, ¡°sanctions aren¡¯t working, what¡¯s the point?¡± My response was always, ¡°define working.¡± If you define it as, ¡°have they forced Russian troops out of Ukraine?¡± then clearly they¡¯ve failed. But if you ask, ¡°have they imposed meaningful costs on the Russian economy?¡± then clearly the answer is yes. The global sanctions and export controls have cost Russia hundreds of billions of dollars, from capital flight to immobilized central bank assets to the billions the Kremlin had to spend to find workarounds.

In reality, the-sanctions-aren¡¯t-working-why-bother argument is straight out Putin¡¯s propaganda playbook. It¡¯s designed to undermine support for the restrictions in the U.S. and Europe.

There were overly optimistic predictions soon after the full-scale invasion that the unprecedented moves would cause Russia¡¯s economy to collapse. That didn¡¯t happen. The Kremlin recovered on the back of the high price of oil, the mainstay of the Russian economy. The Group of Seven nations tried to undermine the stream of petrodollars by imposing a price cap on Russian oil, barring Western services for crude sold over $60 a barrel. It worked for a few months, but then Russia assembled a shadow fleet of tankers to ship crude to Asia, with India gobbling up supplies. And faced with sweeping export controls on U.S. ¡ª and European-designed technology, Russia used shell companies in China, Hong Kong and India to import the chips it needs to produce precision-guided weapons.

Washington¡¯s response has been to play a cat-and-mouse game to close loopholes, targeting middlemen involved in the trade of oil, gold and technology. On Oct. 17, the U.K. stepped up its efforts by blacklisting another 18 tankers, bringing the total number of Russian vessels sanctioned by the West to 90. But the Kremlin has profited from weak enforcement.

Putin would like the world to...