A divided southern flank faces Trump 2.0 and NATO 3.0

The Trump administration and some Northern and Eastern European allies have criticized southern NATO members for not taking the Russian threat—and the demands of alliance solidarity—seriously. This criticism matters more as NATO becomes, in Secretary General Mark Rutte’s words, “more European”: a “NATO 3.0” in which European allies are expected to do more while the United States does less. Yet every NATO member on the southern flank has increased defense spending since 2016, and even more since 2022. Even Spain, the only member to resist NATO’s new target of spending at least 5% on defense and defense-related investments, has nearly doubled defense spending as a share of GDP since 2022, despite Prime Minister Pedro Sánchez’s public defiance of U.S. President Donald Trump. The focus on how much southern NATO members spend, however, risks obscuring a more important question: how effectively are they contributing to regional security?

Southern NATO members—Portugal, Spain, France, Italy, Slovenia, Croatia, Montenegro, Albania, Greece and Turkey—perceive the Russian threat differently than their northern and eastern counterparts. Public opinion polls suggest that while majorities in most countries on the southern flank reject Russia’s war of aggression and therefore support aiding Ukraine, they do not see Russia as an imminent threat to their own security. This helps explain why most Southern Europeans do not seem to support massive and rapid increases in defense spending. The more critical issue is the southern NATO members’ inability or unwillingness to coordinate their strategic assets. Currently, southern NATO member states are too often focused on what divides them rather than what they might do better together.

A divided southern flank

The integration of Europe’s southern states into the Atlantic alliance was never problem-free. Italy and Portugal were both founding members of NATO in 1949, but Italian membership was opposed by those who wanted an exclusively Atlantic-facing alliance. Portugal, because of the Azores Islands, was vital for control of the Atlantic, but the authoritarian Estado Novo government was an awkward fit in an alliance of liberal democracies. NATO’s 1952 enlargement to Greece and Turkey was seen by critics as importing an unresolved conflict into the alliance and as moving it too close to the Middle East. Spain joined NATO in 1982, but its continued membership required a national referendum four years later, in which 52.5% voted in favor and 39.8% against. Indeed, resistance to NATO membership has arisen also from within the south: in Spain, Portugal, France, Italy, Greece, and Turkey, there have been political movements, chiefly on the far left or right, arguing that neutrality serves the national interest better. They may grow, fueled by a global wave of nativist populism.

While it’s apparent that Europe’s southern alliance members have to quickly catch up after years of relatively low defense spending, this is not due to their lack of commitment to NATO. Instead, it is explained by these countries’ low threat perceptions combined with pressure from key allies (like Germany) during the 2011 fiscal crisis to enact draconian spending cuts. Greece was the exception; ironically, at the time, Athens was harshly criticized for “overspending” on defense, despite its location in the conflict-prone Eastern Mediterranean. Now the South is catching up with a degree of fiscal caution that may be excessive, but its recent experience with budgetary crises makes it understandable. Domestic politics also matters: right-of-center governments tend to spend more on defense. But what matters most, given tight budgets, is threat perception: proximity to an aggressive Russia correlates well with how much of GDP European states are spending on defense.

Although Russia’s gray-zone warfare in Europe is intensifying, Southern Europe has seen significantly fewer serious incidents than Northern or Eastern Europe. Portugal, for instance, has recorded Russian cyberattacks, while Spanish authorities believe Russian operatives carried out a targeted assassination. Nonetheless, the southern flank faces growing risks: Moscow backs anti-Western military juntas across the Sahel, whose violence has previously triggered refugee flows northward, while increased Russian naval activity in the Atlantic and the Mediterranean threatens critical subsea cables. According to reporting by El Mundo, the CIA has alerted European governments of the risk of drones being launched against Spain, France, and Italy from the Russian shadow fleet operating in the Mediterranean.

Working around Southern Europe’s divisions

Of course, Southern Europe is not homogeneous. This is where the flexibility of minilateralism becomes so useful. For instance, bilateral relations with Washington vary across NATO’s southern flank. They have visibly improved with Turkey and Greece in recent years but have deteriorated markedly with Spain and, more recently and to a lesser extent, Italy. Italian Prime Minister Giorgia Meloni, who is ideologically close to Trump, has made clear that “being your friend has certainly not helped” her popularity.

Smaller powers such as Portugal and Greece have too much to lose from a rupture with the United States, while medium powers such as France, Spain, Italy, and Turkey appear to believe they have more room to hedge or criticize the current administration. Secretary of State Marco Rubio’s visit to Greece and Portugal in October 2026 publicly displayed appreciation for allies that had allowed the United States access to military bases denied by other countries. The visits also sought to reinforce these partnerships, including through weapons procurement.

From spending to strategy

Where does this leave the southern flank as the Trump administration compels NATO 3.0 to take on the burden of Europe’s conventional defense? Many Southern Europeans hope that this is an episode in the alliance’s long history, rather than a period of permanent U.S. unreliability or hostility. But hope is not a strategy. There will be no return to the past. Europe will need to do more than increase investment in additional capabilities: It will need to develop independent strategic thinking and conceive of a European way of warfare that does not rely on or attempt to replicate U.S. weapons systems and doctrines. Finally, Europe’s collective action problem in foreign and defense policy means that coalitions of the willing are the most realistic shortcut to reordering regional security without significant U.S. involvement. Unfortunately, this is precisely where Southern Europe is weakest.

Turning capabilities into collective strength

What could be done to improve security coordination in Southern Europe? One existing minilateral format already covers most of it: the so-called Med9, inaugurated as the Med7 in 2016. It brings together all of the European Union’s (EU) southern states, from Portugal to Cyprus, and held its latest annual summit of heads of government in October 2026 in Split, Croatia. Turkey, as well as other NATO members not in the EU, are not part of this grouping, whose original purpose was to offer a counterpoint to the “Frugal Four” (Austria, Denmark, the Netherlands, and Sweden) on EU economic governance. Its scope, however, has since widened, with recent agendas and final statements increasingly alluding to security challenges.

Regular meetings of Med9 defense ministers would be the next logical step. They could provide an opening for political dialogue to bridge differences in threat perceptions across the south, particularly between the Eastern and Western Mediterranean, and to identify shared security concerns. These should include maritime security, from port and coastal defense to securing key routes; air defense, including counter-drone capabilities; threats from the Sahel and North Africa; migration management; and the protection of critical infrastructure.

If a Europeanized NATO is to be more than a slogan, southern NATO commands and brigades must be revised, turning capabilities that exist largely on paper into fighting forces that can operate with European assets and troops. Some of the most relevant challenges are discussed by Carlo Masala and Michael O’Hanlon.

Subregional groupings could help. The 5+5 Defense Initiative brings together 10 littoral nations in the Western Mediterranean—five European and five North African—to discuss soft security and confidence-building. Its four NATO members—Portugal, Spain, France, and Italy—could and should build on that experience by coordinating regular staff talks, exercises, and planning for regional deterrence and defense. Ideally, a similar arrangement would be created for the Adriatic and the Eastern Mediterranean, if Greece and Turkey could be convinced to work together.

So far, though, new developments have been limited and bilateral. Portugal and Greece, for example, have decided to buy new frigates from Italy and to hold defense consultations with Rome. Some Southern Europeans, sensitive to the negative perceptions often associated with the south, seem to fear being associated with any southern grouping. This represents a significant missed opportunity.

Southern European countries could contribute more to NATO 3.0. They could provide strategic depth for reserves, production, and logistics against threats to the east or north; play a key role in providing maritime security and securing routes for critical raw materials; and act as a barrier against threats from the south. It would require not just more investment but a degree of regional coordination that Southern Europe has not even begun to pursue. At a time of proliferating tensions and conflicts—and an explosion of minilateralism elsewhere in Europe—this inertia is baffling. The alternative is stark: Southern Europe will continue to be strategically defined by others and potentially defended by no one. Southern Europeans should stop complaining about being misrepresented and misunderstood by others and start getting their own house in order.