The wars in Ukraine and the Middle East are existential threats to Europe as a peace project. Leaders and citizens must reaffirm their solidarity to meet today's multifaceted challenges, writes Mark Pierini on the Carnegie Endowment for World Peace website.
Four years ago, Russia launched an unprovoked war against Ukraine. The war continues with unabated force, as Moscow seeks to gain territory while weakening NATO and the EU. Meanwhile, in this year's war against Iran, Israel has shown absolute determination, and the United States has demonstrated uncertain tactics, initially ignoring Western Europe. In both cases, European leaders - whether from NATO or non-NATO countries, EU members or non-members - showed a strong reluctance to engage in full-scale war. There is both an explanation and a justification for this attitude.
The traumas of the past
The not-so-distant history of Europe provides an explanation. For most of the first half of the twentieth century, Western Europe was at war, and millions of its people were killed or displaced and destroyed. All families in Europe have carried this collective pain ever since, as I recently documented in a memorial booklet (in French).
After the end of World War II, a grand effort was made to rebuild European economies with US help through the Marshall Plan, to organize international relations through the UN Security Council and other multilateral institutions, and to promote peace and reconstruction in Europe through the project that became the EU. Europeans embraced the motto of "never again". To this day, this past remains the driving force behind the EU's efforts and its collective economic and military support for Ukraine.
But the collective memory of the war has faded. So has the perception of threat since the collapse of the Soviet Union. As a result, "never again" has become less attractive to younger generations, as Polish Foreign Minister Radosław Sikorski noted last December.
This evolution has been accompanied by a collective sense of relief following the fall of the Soviet Union and the accession of most Central and Eastern European countries to the EU and NATO. Meanwhile, under President Vladimir Putin, Russia has undertaken a systematic effort to undermine NATO's defenses and offers ideological and financial support to far-right governments and political parties that take anti-EU and anti-NATO positions. Today, the effects of this policy are visible, for example, in Hungary's active opposition to EU support for Ukraine.
Most recently, Donald Trump's second US presidency, from its very beginning, expressed strong disagreements with NATO and the EU. US Vice President J.D. Vance's speech at the Munich Security Conference in February 2025 was an unexpected turning point - to the point that several European leaders were left in a state of distrust.
But the distrust did not last long. The US National Security Strategy, published in early December 2025 with Trump's seal and signature, not only confirmed the criticism of Western European countries, but also began a deliberate ideological war against the political and economic architecture of the EU. This hostile document also signaled that US diplomats would prioritize working with "patriotic" governments and parties. This policy has been expressed in cabinet-level visits in support of the most anti-EU and anti-NATO politicians and parties, such as the Hungarian prime minister and the "Alternative for Germany".
Trump's second presidency has not stopped at provocative policy documents. It has been followed by sharp statements unbecoming of a centuries-old ally, such as the astonishing claim that European troops deployed in Afghanistan as part of NATO's presence there from 2001 to 2014 had avoided the front lines. The president has made similar claims about Europe's involvement in the war against Iran, adding: "WE WILL REMEMBER!"
Today's rift
More fundamentally, Europe's attitude towards endless wars is justified. The mantra of "never again" is what drove the work of a small group of European politicians in the late 1940s, leading to the bold Schuman Declaration and the equally bold European Coal and Steel Community. Six of the belligerents of World War II - Belgium, France, Italy, Luxembourg, the Netherlands and West Germany - decided to delegate the management of the two most important resources for Europe's reconstruction to a multinational body composed of senior officials and overseen by ministers from the member states' governments.
This was the first step towards European economic integration and common policies. It took many millions of dead and wounded across Europe to make leaders make a strong political decision to consolidate peace, manage reconstruction, and organize a joint effort to restore prosperity.
I vividly remember a discussion in mid-2025 when one of the three US ambassadors in Brussels told a small group of think tanks that he had yet to hear a good explanation for why the EU was created. I indulged in... recalling the rationale for Europe’s aversion to war and suggesting that my own family history exemplifies the common past of European citizens: a great-uncle who was a front-line artilleryman at the Battle of Verdun in 1914; a father arrested in 1940 for aiding a resistance fighter against Mussolini before being rehabilitated in 1945; another uncle who led a network of resistance in the Southern Alps, clearing the way for American troops before their landing in July 1944 in southeastern France; and a father-in-law who is believed to have been killed in action in May 1940 in the Somme Valley but was eventually rescued by his own troops. This is not an exceptional story; it is the fate of everyone across Europe. And it has become "never again".
Back to the future, the rearmament of Europe is already underway, as total dependence on the American security umbrella is a thing of the past. Many decisions on rearmament have been made at several levels: by the EU, by the Coalition of the Willing, which supports Ukraine, and by smaller groups of countries, including Canada. But rearmament is by definition a long-term process.
In the short term, what emerges from recent developments in transatlantic relations and internal developments in Europe is a set of three watershed moments.
First, what was unthinkable for eighty years has already happened. The personal ties of European leaders with a US president have been irreparably damaged. Even if dialogue with the Trump White House continues, trust has been broken, and relations will become more distant and less personal as a result. The Israeli-American war against Iran has made matters worse.
Second, Moscow’s long-term efforts to undermine Western Europe, the EU, and NATO through its support for far-right governments and political parties have led to the rise of pro-Russian, anti-European forces across the continent. Neither NATO nor the EU is likely to be obliterated, but their survival will require drastic changes.
Third, the EU’s political architecture is incapable of addressing the security challenges we have faced since February 2022 on its own. The EU has proven too slow to process decisions and unable to reach unanimity due to the bloc’s voting rules and internal dissent. It has had to counter Hungary’s complicity with the Kremlin and the Trump White House. It has had to devise new financial arrangements to allow for higher security spending. It has even witnessed a reverse Brexit and brought the UK back into ad hoc security formats. And it has included other actors, such as Canada, Iceland and Norway, in policy development and security commitments. These short-term measures have succeeded in meaningful ways, but they have also exposed structural weaknesses. Corrective action is needed in the manner suggested by Stefan Lehne of Carnegie: "The EU is structurally incapable of responding to today's foreign policy crises. The Union should incorporate the European External Action Service (EEAS) into the European Commission and create a Security Council better equipped to take action on the world stage."
In the long term, European leaders – not just the EU, but also Iceland, Norway and the UK, plus Ukraine and Moldova – must now learn the lessons of recent events. Externally, this means dealing with a persistently hostile Russia; reckoning with an ideologically hostile United States, including the affinity between its president and the Russian leader; and dealing with a multi-sided conflict in the Middle East and its economic impact. Internally, this means renewing Europe’s institutional architecture to avoid dead ends resulting from the actions of current or future disruptors, and considering new formats for policy development that would include countries like the United Kingdom or Ukraine in specific circumstances.
All these changes must be orchestrated while preserving the rule of law and Europe’s democratic architecture.
The challenge of tomorrow
Undoubtedly, these priorities constitute a difficult agenda for European leaders, and many doubts have been expressed about their ability to deal with this multifaceted challenge.
The current political landscape of Europe has been aptly described by many authors recently. It is worth quoting the posts of two of my compatriots from 2025. French historian Sylvain Kahn notes: "The Atlantic Alliance died in 2025. Europeans are alone, but together in peace and far from isolated. Their future depends on their wisdom and choices." Meanwhile, former French Prime Minister Alain Juppé writes: "I am convinced that there is another way [than war]: to proudly affirm who we are and to consolidate what unites us. What unites us is stronger than what divides us. The very memory of our past battles creates a bond between us: We have fought so many wars among ourselves that we want to be a force for peace."
Ultimately, Europeans of all ages - leaders and citizens - must remember the promise made immediately after the Second World War: NEVER AGAIN!