When Vladimir Putin worked in Dresden, he watched helplessly as Soviet ally East Germany slipped out of Moscow’s orbit, united with West Germany, and joined the democratic side of Europe. Soviet-dominated multilateral institutions in Europe — the Warsaw Pact and the Council for Mutual Economic Assistance (Comecon), the Soviet command economy trade organization — also disappeared. Putin then witnessed the dissolution of the Soviet Union, an event that he later described as one of the greatest tragedies of the 20th century. Former Soviet allies and parts of the Soviet empire peeled away, also joined the democratic side of Europe and eventually became members of NATO and the European Union. For nearly three decades, the West was consolidating as the East was disintegrating. The momentum toward a Europe whole and free was so powerful that earlier Russian leaders even flirted with joining as well.

That trend has now reversed. The decision by a majority of British voters to exit the European Union was not the first event in this reversal but maybe the most dramatic. Europe is now weakening as Russia, its allies and its multilateral organizations are consolidating, even adding new members. Putin, of course, did not cause the Brexit vote, but he and his foreign policy objectives stand to gain enormously from it.

Most importantly, one of the European Union’s most principled critics of Russian aggression in Europe will no longer have a vote in Brussels. That’s good for Putin’s interests and bad for U.S. national interests. Boris Titov, Russia’s commissioner for entrepreneurs’ rights, who is hardly a militant nationalist by Russian standards, made the argument most clearly when he cheered on Facebook, “UK out!!! In my opinion, the most important long-term consequence of all this is that the exit will take Europe away from the Anglo-Saxons, that is, from the USA. This is not the independence of Britain from Europe, but the independence of Europe from the USA.” London also helped advance our common interests inside the E.U. on non-European security issues from Iran to Libya to as far away as the Pacific. That “Anglo-Saxon” perspective is now lost within this most important international organization.

During a question and answer session at the St. Petersburg International Economic Forum, President Vladimir Putin said Russia did not want a new Cold war with the West and did not like to think it was slipping into one. (Reuters)

The U.K. exit also removes one of the E.U.’s most capable members. Whether it was Britain’s world-class military or its skilled diplomatic corps, the U.K. contributed greatly to an array of E.U. missions over the years, despite its complicated relationship with Brussels. Removing those resources, personnel and assets from the E.U. will ultimately weaken the organization, an outcome that serves Putin’s political purposes.

To be sure, the British government will continue to engage the E.U. and European capitals on foreign policy matters of mutual interest, just as the United States does now. But having a seat at the table with a vote and a veto is different from trying to influence those sitting at the table. The jobs of diplomats from E.U. countries seeking greater accommodation with Moscow just got easier. The job of E.U. diplomats fighting to resist Russian aggression, especially those from Estonia, Latvia and Lithuania, just got harder.

The first test will come over sanctions against Russia for annexing Crimea and intervening in eastern Ukraine in support of separatists. Moscow Mayor Sergei Sobyanin made clear his prediction: “Without Great Britain in the E.U., no one will so zealously defend the sanctions against us.” Let’s hope he is wrong.

Second, other pro-Putin, anti-E.U. politicians and movements throughout Europe just became a little stronger. Marine Le Pen, whose National Front party is partially financed by a Kremlin-friendly Russian bank, celebrated the U.K. referendum result. Other nationalist, xenophobic, isolationist leaders and parties on the continent who share her views already have begun to call for E.U. exit referendums in their countries. Even the process of debating these initiatives will weaken European unity. And here in the United States, it is no coincidence that presumptive Republican presidential nominee and Kremlin favorite Donald Trump has lined up with Le Pen and her ideological allies in praising the U.K. referendum result.

Third, new doubts about the utility of E.U. membership also weaken Putin’s opponents in Ukraine. Those who amassed on the Maidan in fall 2013 were demanding the very thing that British voters rejected — closer ties to the European Union. The ideas of these pro-European voices inside Ukraine now will face increasing scrutiny from E.U. skeptics, who will ask why Ukraine should seek to join a club that others are leaving. This same debate will play out in other countries contemplating E.U. membership.

Fourth, America’s closest ally when voting in multilateral forums, pressing diplomatically on global security issues and championing democratic values just became a little weaker. That’s a win for Putin. And who knows when the damage will end. The British economy will contract in the short term, and maybe longer. Scotland could split away. Even the future of Northern Ireland is unknown. At a minimum, our special partner will be distracted for years in managing these internal challenges and the negotiations with Brussels over its exit. More dangerously, the United Kingdom could end, as Scotland ponders another referendum. Such a dismantling would dramatically reduce the power and stature of one of our closest allies. Former prime minister Margaret Thatcher correctly observed, “The Anglo-American relationship has done more for the defense and future of freedom than any other alliance in the world.” But the best days of our special relationship might be behind us.

In parallel to European fissures, Putin is consolidating strength. He has restored autocratic rule at home, crushing all serious dissent and mobilizing popular support through foreign war. He stopped NATO’s expansion by invading Georgia in 2008 and slowed E.U. expansion by invading Ukraine in 2014. He has increased Russia’s economic hegemony in large parts of the former Soviet Union by building the Eurasian Economic Union (EEU). As a result of his military intervention in Syria, Putin is expanding Russia’s presence in the Middle East, as Europe and the United States pull back. Most amazingly, his model of government and style of leadership now inspire European admirers, both in a handful of governments and in some societies.

Will these dual trends of European disintegration and EEU integration continue for another 30 years, just as the opposite two trends endured for three decades? Probably not. In the long run, Russia remains plagued by too many internal challenges and skittish EEU partners, while we in the West will find ways to recalibrate our cooperation. But the short-term shift in the balance of power between a united democratic Europe and an illiberal Russia is obvious, and troubling.