Of all the lessons that can be drawn from the year that has passed since Russia invaded Ukraine, one stands out: global interdependence does not guarantee peace, and must be adapted to the realities exposed by recent events.

According to Harvard's Joseph S. Nye, Jr., and Princeton's Robert O. Keohane, interdependence refers to the relationship of mutual dependence that develops between states as a result of their interactions, especially economic and trade ties. Given the intertwined nature of markets and politics (including geopolitics), states end up needing one another to bolster their security (including energy security) and achieve economic growth and development.

In recent decades, interdependence has held a privileged position in Western political thought. While a revision of the concept is inevitable, to ignore the positive contribution that interdependence has made to promoting global stability and security in Europe since the end of World War II would be dishonest and unproductive.

The success of the European project is due in large part to the virtues of interdependence. The development of trade and commercial ties facilitated the establishment of common interests between European countries, bringing decades of peace to a continent previously ravaged by war - an achievement worth celebrating.

Interdependence was also the bedrock on which German Chancellor Willy Brandt built Ostpolitik, launched in 1969. Brandt took a chance on the idea - risky at the time - that deeper diplomatic and economic relations between the Soviet Union and the West would reduce the likelihood that the Cold War would turn hot. It turned out to be a diplomatic masterstroke: the policy helped to ease tensions between the two sides.

By the beginning of this century, globalization was advancing rapidly. Economic interdependence was widely viewed in the West as synonymous with global stability - a belief that endured even when events like the terrorist attacks of September 11, 2001, in the United States highlighted the risks that globalization entailed. In fact, China was welcomed into the World Trade Organization just three months after 9/11, demonstrating the West's continuing faith in the potential of interdependence for rapprochement.

But Russian President Vladimir Putin has shown how leaders can leverage interdependence to pursue coercive tactics. Ukraine has always been central to Putin's imperial ambitions. In the last decade, Ukraine has been the subject of debate not only over its place in European security arrangements, but also about its position in a world increasingly defined by trade relations.

Putin spent years boosting trade with the former Soviet countries and the rest of Europe, not to strengthen the foundations of peace on the continent, but to increase Russia's geopolitical influence. In this regard, the creation of the Eurasian Customs Union in 2010 was a crucial step in Putin's strategy of replicating the Soviet Union by other means (namely trade).

But Ukraine chose not to join the customs union, instead pursuing an Association Agreement with the European Union. Putin would not tolerate such a prospect, pressuring then-Ukrainian President Viktor Yanukovych to suspend preparations for the Association Agreement in late 2013.

Arguably, this was the moment when the Russian war against Ukraine started. In February 2014, thousands of Ukrainians gathered in Kyiv's Independence Square to protest the decision. The so-called Revolution of Dignity ended up driving Yanukovych from power, raising fears in the Kremlin that Russia was losing Ukraine. Within a month, Russia had annexed Crimea, and Russia-backed separatists had started a war in Ukraine's eastern Donbas region. Last February's full-scale invasion marked the beginning of a tragic new chapter in that war.

Yet even in the days immediately preceding the invasion - when hundreds of world leaders, but no Russian delegation, gathered for the Munich Security Conference - the idea that Russia would attack was met with some incredulity. This is partly because, despite the horde of Russian troops massed at Ukraine's border, faith in the deterrent power of interdependence remained strong.

If Russia went to war against Ukraine, observers noted, it would face astronomical economic costs. The rest of the global economy, too, would suffer mightily. Shortly thereafter, that hope in the pacifying logic of interdependence proved unfounded.

A year after the Russian invasion of Ukraine, it is now clear that interdependence alone cannot serve as a stable foundation for peace, or even rapprochement. Trade and commercial ties may help to align countries' interests, but they do not create responsible geopolitical actors. On the contrary, for it to be constructive, interdependence presupposes responsible political leaders.

With Russia's invasion of Ukraine, we Europeans have discovered that interdependence, or rather dependencies, can make us more vulnerable than we thought. The lesson is clear: we must take greater care in choosing our interdependencies. The EU, long a champion of interconnectedness, has taken this to heart, especially when it comes to energy. The changes have been rapid, sharp, and laudable: in just a year, the EU has decreased the share of piped Russian gas in its total supply from 40% to just 8%.

The EU must also reduce its potentially risky dependencies in other strategic sectors, such as health, defense, and technology. At the same time, however, it must sustain - and even continue to deepen - its engagement with the rest of the world. As German Chancellor Olaf Scholz wrote before his trip to Beijing last November, Europe must avoid overreliance on its competitors, such as China, but should not seek to sever ties.

In the last year, we have learned that interdependence cannot prevent war. But we also know that rejecting interdependence is the antithesis of the European project and incompatible with the multilateralism needed to solve global problems. However interdependence is reconceived in the coming years, it will remain essential to Europeans' core interests and major goals.

From Project Syndicat