By Nicu Popescu & Fredrik Wesslau
For decades, much of Europe viewed military engagement through the lens of NATO or the EU, since these structures have long shaped how Europeans thought about conflict, deterrence, and security. But the wars in Ukraine and the Middle East have exposed the limits of this approach. With cracks appearing in traditional alliances, new coalitions of the willing, partnerships, and security guarantees for countries outside established strategic frameworks are giving rise to a cat’s-cradle architecture of European security.
Ukraine illustrates this evolution most clearly. Instead of entering a formal alliance with Ukraine, Europeans have spun an intricate web of treaties and commitments offering varying degrees of reassurance and financing.
Together, more than 20 bilateral security agreements have codified military support to Ukraine and established a “coalition of the willing” that will contribute to that country’s security after a ceasefire. Similarly, in the Middle East, European countries have deployed forces in a bid to protect Gulf infrastructure and maintain regional stability.
While France has taken the most visible stance, the UK and the Netherlands have also sent ships, air-defence systems, aircraft, and other capabilities to help defend Qatar, the UAE, and Saudi Arabia. Meanwhile, a wide range of countries—including the UK, France, Germany, Italy, the Netherlands, Denmark, Latvia, Slovenia, Estonia, Norway, Sweden, Finland, the Czech Republic, Romania, Lithuania, and several partners outside the EU—have committed to helping ensure freedom of navigation and regional security after the war.
These European responses point to several new tendencies. The ad hoc coalitions that are emerging increasingly stretch across established alliance lines. The logic behind these choices is clear. Ukraine’s security has become central to Europe’s own. If Russia wins its war, resumes its attack after a ceasefire, or sets its sights on other regional targets, the threat to Europe would be immediate and severe.
A Russian-controlled Ukraine—with all its natural resources, human capital, and industrial capacity—would represent an existential strategic challenge not only for Poland and Germany, but also for the rest of Europe. Europeans need to engage wherever their interests are directly at stake, including beyond the traditional alliance perimeter.
Europe’s accession states (those pursuing EU membership) remain “grey spots” on the map—strategically important, but, in this new world of flexible coalitions and shifting alliances, insufficiently protected. The most critical is Moldova. After providing Ukraine and the Gulf monarchies with various securi ty guarantees, it is only reasonable that Europe would design a similar architecture to ensure Moldova’s peace and security, given the country’s implications for European security.
Developments in recent months have shown why European security guarantees are necessary. In March, a Russian strike on a Ukrainian hydropower dam caused a massive oil spill in the Nistru River, contaminating Moldova’s main water supply. Moldova’s second-biggest city and multiple districts were left without clean water for weeks.
Then, a Russian drone strike on Ukrainian territory damaged part of Moldova’s electricity interconnector with Romania, underscoring a continuing risk from the war. Clearly, Russia has determined that it will face no costs for such behaviour. Despite these pressures, Mol dova has stood fi rm. In March, it formally launched the process of joining the coalition of the willing supporting Ukraine—a remarkable step for a constitutionally neutral country.
Another key region is the Western Balkans. With defence spending rising and geopolitical fault lines deepening, the risk of destabilisation cannot be ruled out. Establishing coalitions of the willing to provide reassurance or collective security commitments to all accession states could help maintain stability and calm anxieties.
Europe should formally guarantee the existing borders in the region, which would bolster its own credibility as a guarantor of peace, both within its borders and along its frontier. Europe’s security order needs to be reconstituted. In a world of fracturing alliances, closer security partnerships with a wider range of states, however small, will increasingly become a source of power, allowing Europe to defend its interests wherever they are at stake.
Deepening defence links with EU accession states and offering security guarantees should be a top priority. Nicu Popescu is a former deputy prime minister of Moldova. Fredrik Wesslau is Acting Director of the European Policy Institute in Kyiv.