President Vladimir Putin’s impulsive incursion into Ukrainian territory has left Russia more isolated than at any time since the Cold War. Predictably, the European Union and the United States have loudly objected. More to the point, however, no country has rallied to Russia’s defense.

Such deafening silence reflects the degree to which Putin’s thinking is out of step with the modern world. With this action, Putin has revealed himself to be an imperial thinker in a post-colonial world.

Putin grew up at a time when Russia was the unquestioned center of a communist empire that had managed to suppress national challenges for decades. So while the rest of the world was dismantling their empires and transforming colonies into nations, the Soviet Union retained its empire until 1991. Putin — as the leading representative of the last Soviet generation — acquired the mindset of Russia’s natural hegemony and never accepted the post-Soviet republic’s place in the expanding community of nations.

For centuries the world order was built on the “imperial right” of the strong to rule over and “take care” of weaker peoples and lands. Colonies contributed to the wealth, prestige and power of the imperial center, and the last two great overseas empires — British and French — inherently believed in their rights to intervene militarily if certain fundamental national or economic interests were at stake.

In the aftermath of World War II, however, the British and French empires both collapsed. Though political and cultural ties remain between the former imperial nations and their ex-colonies, France and Britain no longer assert a mandate to control other countries.

Russia has been the one outlier in this process of decolonization. Its continental empire had expanded steadily under both tsars and Soviets to incorporate the surrounding national and ethnic groups. Like colonies, these conquered regions contributed significantly to Russia’s economic wealth and defense.

The Soviet Union further extended its military empire after World War II to include Eastern Europe. This external empire fell apart in 1989 and two years later the Soviet Union finally collapsed, replaced by 15 new sovereign nations.

Putin has at times expressed nostalgia for the Soviet Union and its old imperial ways. With the noticeable exception of his invasion of Georgia, however, Putin has been reluctant to play the imperial card in his foreign policy.

Even the creation of the vaunted Eurasian Union has been painstakingly slow and overly bureaucratic, as Moscow has tried to convince Belarus and Kazakhstan to integrate the three economies. Kazakhstan, in particular, does not want to be treated like a former colony. President Nursultan Nazarbayev insisted at the most recent meeting of the three countries that any new Eurasian Union should not be able to bind its members in international agreements and that each state must retain sovereignty.

The potential loss of Ukraine as a member of the Eurasian bloc, however, unleashed Putin’s innermost imperial thoughts. Ukraine strikes a unique chord in the heart of many Russians. It provides a historic and civilizational link for Russia — extending back to its origins in Kievan Rus.

A Ukraine aligned with Russia also represents Moscow’s last chance at great power status. That is why Putin wants Ukraine in the Eurasian Union, and why Putin could not allow Ukraine to sign a free-trade agreement with the European Union.

So Putin responded reflexively to the crisis in Ukraine, dismissing more than two decades of national sovereignty and asserting Russia’s imperial right to defend ethnic Russians anywhere it so chooses. Such an outlook is an anachronism to the modern world, long separated from 19th and 20th century colonial rule.

Putin however, represents a generation that was raised and educated when the Soviet empire was at its height. He even worked as an imperial functionary (a spy) during his time in East Germany. There should be little surprise that he still harbors an imperial mentality.

But the serious problem now is that Putin has acted on these beliefs. And they have produced a backlash that will define his presidency.

Ironically, by violating Ukraine’s sovereignty and threatening its borders, Putin has now done more to promote Ukrainian identity than any current national politician could have ever imagined. He has also forced the European Union and the United States to make a major financial commitment to Ukraine’s economic development — making it almost certain that the new Kiev government can now pursue the free trade area with the European Union that Putin so desperately tried to stop.

His decision to treat Crimea like a colonial outpost and accept the flawed referendum’s results means that he will facilitate a violation of international law that no other country will recognize.

Russia may soon find itself on the outside looking in — starting most obviously with the G8 — after it has struggled so hard to be recognized as an essential member of the international community.

In addition, Putin has opened a Pandora’s box that will undermine the country’s federal construction. The Russian Federation possesses major ethnic divisions within its borders — its own internal empire, as it were. Following Crimea’s example, other national groups in Russia may feel equally empowered to demand increased regional sovereignty, if not actual independence.   Russia now has adopted a principle that works directly against its own internal unity.

Putin’s imperial overreach also comes with real economic costs. His $50 billion investment in Sochi as a tourist attraction disappeared in a week. He will instead have to subsidize a rival tourist location in Crimea — where vacationers (if they come) will have to contend with an occupying army for the immediate future.

International investors will also view the Russian market with increased skepticism, especially after the Duma threatened foreign companies with the confiscation of their property if Western sanctions were imposed. Russian citizens will continue to vote with their money and send it abroad, depriving Russia of the very resources it needs to expand its economy and become a global power.

Putin believes that he can survive all these developments. His political grip on the country is still so strong that, in the short-term, he may be right.  His decision to play the imperial card, however, shows a man who is out of touch with the times. The people of Crimea, Ukraine and Russia will pay a heavy price for his imperious gesture.

This article originally appeared on Reuters.