Looking back over the past quarter-century, it isn’t easy to name a Western policy that can truly be described as a success. The impact of Western development aid is debatable. Western interventions in the Middle East have been disastrous.

But one Western policy stands out as a phenomenal success, particularly when measured against the low expectations with which it began: the integration of Central Europe and the Baltic States into the European Union and NATO. Thanks to this double project, more than 90 million people have enjoyed relative safety and relative prosperity for more than two decades in a region whose historic instability helped launch two world wars.

These two “expansions,” which were parallel but not identical (some countries are members of one organization but not the other), were transformative because they were not direct leaps, as the word “expansion” implies, but slow negotiations. Before joining NATO, each country had to establish civilian control of its army. Before joining the European Union, each adopted laws on trade, judiciary, human rights. As a result, they became democracies. This was “democracy promotion” working as it never has before or since.

But times change, and the miraculous transformation of a historically unstable region became a humdrum reality. Instead of celebrating this achievement on the 25th anniversary of the fall of the Berlin Wall, it is now fashionable to opine that this expansion, and of NATO in particular, was mistaken. This project is incorrectly “remembered” as the result of American “triumphalism” that somehow humiliated Russia by bringing Western institutions into its rickety neighborhood. This thesis is usually based on revisionist history promoted by the current Russian regime — and it is wrong.

For the record: No treaties prohibiting NATO expansion were ever signed with Russia. No promises were broken. Nor did the impetus for NATO expansion come from a “triumphalist” Washington. On the contrary, Poland’s first efforts to apply in 1992 were rebuffed. I well remember the angry reaction of the U.S. ambassador to Warsaw at the time. But Poland and others persisted, precisely because they were already seeing signs of the Russian revanchism to come.

When the slow, cautious expansion eventually took place, constant efforts were made to reassure Russia. No NATO bases were placed in the new member states, and until 2013 no exercises were conducted there. A Russia-NATO agreement in 1997 promised no movement of nuclear installations. A NATO-Russia Council was set up in 2002. In response to Russian objections, Ukraine and Georgia were, in fact, denied NATO membership plans in 2008.

Meanwhile, not only was Russia not “humiliated” during this era, it was given de facto “great power” status, along with the Soviet seat on the U.N. Security Council and Soviet embassies. Russia also received Soviet nuclear weapons, some transferred from Ukraine in 1994 in exchange for Russian recognition of Ukraine’s borders. Presidents Clinton and Bush both treated their Russian counterparts as fellow “great power” leaders and invited them to join the Group of Eight — although Russia, neither a large economy nor a democracy, did not qualify.

During this period, Russia, unlike Central Europe, never sought to transform itself along European lines. Instead, former KGB officers with a clearly expressed allegiance to the Soviet system took over the state in league with organized crime, seeking to prevent the formation of democratic institutions at home and to undermine them abroad. For the past decade, this kleptocratic clique has also sought to re-create an empire, using everything from cyberattacks on Estonia to military invasions of Georgia and now Ukraine, in open violation of that 1994 agreement — exactly as the Central Europeans feared.

Once we remember what actually happened over the past two decades, as opposed to accepting the Russian regime’s version, our own mistakes look different. In 1991, Russia was no longer a great power in either population or economic terms. So why didn’t we recognize reality, reform the United Nations and give a Security Council seat to India, Japan or others? Russia did not transform itself along European lines. Why did we keep pretending that it had? Eventually, our use of the word “democracy” to describe the Russian political system discredited the word in Russia itself.

The crisis in Ukraine, and the prospect of a further crisis in NATO itself, is not the result of our triumphalism but of our failure to react to Russia’s aggressive rhetoric and its military spending. Why didn’t we move NATO bases eastward a decade ago? Our failure to do so has now led to a terrifying plunge of confidence in Central Europe. Countries once eager to contribute to the alliance are now afraid. A string of Russian provocations unnerve the Baltic region: the buzzing of Swedish airspace, the kidnapping of an Estonian security officer.

Our mistake was not to humiliate Russia but to underrate Russia’s revanchist, revisionist, disruptive potential. If the only real Western achievement of the past quarter-century is now under threat, that’s because we have failed to ensure that NATO continues to do in Europe what it was always meant to do: deter. Deterrence is not an aggressive policy; it is a defensive policy. But in order to work, deterrence has to be real. It requires investment, consolidation and support from all of the West, and especially the United States. I’m happy to blame American triumphalism for many things, but in Europe I wish there had been more of it.

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