Deterrence and defense in the Euro-Atlantic

Developing policy recommendations for deterring and defending against aggression aimed at allies and partners in the European theater.

About

The Transatlantic Security Initiative is committed to:

  • Supporting NATO’s continued status as the world’s most successful political-military alliance
  • Addressing implications of Russia’s ongoing invasion of Ukraine for transatlantic security
  • Working with allied militaries to ensure fully resourced defense plans and a battle-ready alliance under any scenario
  • Supporting transatlantic defense innovation and industrial cooperation
  • Enhancing defense policy coordination between NATO, allied governments, and other key institutions such as the EU
  • Confronting challenges to regional security across the Euro-Atlantic area, in particular the Arctic, the Nordic-Baltic region, the Black Sea, and the southern flank
  • Countering Russian hybrid threats and malign activity across the Euro-Atlantic, including CBRN threats

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Featured highlights

Trackers and Data Visualizations

Jun 20, 2025

NATO defense spending tracker

By Kristen Taylor, Julia Salabert

The Transatlantic Security Initiative’s NATO defense spending tracker delves into data and figures to analyze current defense spending trends.

Europe & Eurasia NATO
Private Event Thu, June 25, 2026 • 1:45 pm ET

NATO Secretary General Mark Rutte on the Ankara Summit Agenda

AN AC FRONT PAGE EVENT—NATO Secretary General Mark Rutte lays out his priorities for the upcoming Ankara summit.

Central Europe Eastern Europe Europe & Eurasia European Union

Ankara Summit Content Series

How European NATO allies are stepping up, by the numbers

This year’s NATO Summit takes place at a critical time for the Alliance. With no marquee deliverable like last year, NATO leadership will point to progress from European allies on defense spending, defense industrial production, and aid to Ukraine.

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European allies can boost NATO unity at the Ankara summit by accelerating eastern flank deterrence

Ahead of the upcoming summit, European allies should commit to accelerating their deployment of full-strength combat brigades to the Baltic states by 2027.

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NATO allies need a plan for addressing threats below the threshold of war

NATO should take on a more active role in coordinating the response to attacks below the threshold of war. Specifically, the Alliance should use the upcoming NATO Summit in Ankara to establish response options for its member states.

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The Ankara summit is an opportunity for NATO to ramp up engagement with its southern neighborhood

NATO’s engagement with its southern neighborhood has been inconsistent, despite growing security challenges. The Ankara summit offers and opportunity to strengthen dialogue with regional partners and reinforce NATO’s southern strategy.

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Innovation ranges: How NATO can test and deploy cutting-edge capabilities faster

The Ankara summit offers allies an opportunity to absorb the lessons from innovation ranges and revitalize the defense innovation pipeline.

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Civilian infrastructure is now a strategic target. NATO must adapt to protect it.

To help build resilience, NATO allies should integrate Nordic, Baltic, and Ukrainian “total defense” practices into NATO planning and exercises.

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Europe should take the long bet on the US and the transatlantic security relationship

At the upcoming Ankara summit, European allies should underscore their increased defense spending and their tangible contributions to shared security.

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How NATO can strengthen the transatlantic defense industrial base in Ankara and beyond

The NATO Summit in Ankara is an opportunity to advance a stronger, more integrated transatlantic defense industrial base.

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Europe’s no-panic playbook for a radically different US foreign policy

NATO and the EU need to make significant, lasting changes in response to Trump 2.0 national security policy–quickly, and ideally in coordination with Washington.

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NATO’s new Arctic presence shows that European allies are stepping up

Heading into the Ankara summit, the Arctic region offers a prime example of where European allies are stepping up and laying the groundwork for deeper cooperation.

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More European NATO allies should step up help to Ukraine through PURL

NATO’s Ankara summit is an opportunity for allies to expand participation in the Prioritized Ukraine Requirements List (PURL), which funds US-made military equipment for Ukraine.

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NATO can emerge from the Ankara summit stronger. Here’s how.

Allies can strengthen the Alliance by continuing to increase defense spending, accelerating joint capability development, and sustaining their support for Ukraine.

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Analysis

Deterrence and defense in the Euro-Atlantic

Report Jun 10, 2026

The future of NATO’s deterrence in the air domain

By Edward Brady

European NATO member states need to prepare to deter, and if necessary, defeat Russia—with less US support. When it comes to airpower, here are the actions European states need to take in the short, medium, and long term. 
Defense Policy Europe & Eurasia
Deterrence and defense in the Euro-Atlantic

Report Feb 12, 2026

Putin’s next move? Five Russian attack scenarios Europe must prepare for

By Richard D. Hooker, Jr.

Whether emboldened by victory in Ukraine or motivated by a loss to pursue success elsewhere, Russian president Vladimir Putin is likely to continue his campaign of aggression. The Nordic and Baltic region, already subject to a campaign of intimidation, is in the Kremlin’s crosshairs—with these five places at greatest risk.
Defense Policy Eastern Europe
Deterrence and defense in the Euro-Atlantic

Dispatches Jun 23, 2026

How European NATO allies are stepping up, by the numbers

By Kristen Taylor, Matt Trunkey

Expect NATO leadership to focus on three main issues: defense spending, defense industrial production, and aid to Ukraine.
Defense Industry Defense Policy
Deterrence and defense in the Euro-Atlantic

Dispatches Apr 20, 2026

Five ideas to make the upcoming NATO Summit in Ankara a success

By Atlantic Council experts

While the upcoming summit is unlikely to produce anything as singularly significant as 2025’s “5 percent” pledge, there are important steps the Alliance should take.
Europe & Eurasia NATO
Deterrence and defense in the Euro-Atlantic

Dispatches Dec 15, 2025

How Europe can strengthen its own defenses and rebalance transatlantic relations

Europe should advance a new security architecture aimed at strengthening its own defense while continuing to cooperate with the United States in areas of mutual interest.
Defense Industry Defense Policy
Deterrence and defense in the Euro-Atlantic

Issue Brief Jun 2, 2025

For NATO in 2027, European leadership will be key to deterrence against Russia

By Scott Lee, Andrew Michta, Peter Jones, and Lisa Bembenick

NATO lacks the operational integration, logistics, and joint force capabilities needed to quickly counter Russian mass and tempo near its borders. With the United States increasingly focused elsewhere, how can the Alliance retain military superiority in 2027 without overreliance on US military might?
Defense Policy Europe & Eurasia

About the program

The Transatlantic Security Initiative aims to reinforce the strong and resilient transatlantic relationship that is prepared to deter and defend, succeed in strategic competition, and harness emerging capabilities to address future threats and opportunities.

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