NATO Exercises 2025: The Complete Guide to Allied Readiness

Bookmark this page for the authoritative, always-updated overview of NATO’s 2025 training calendar—drill dates, domains, and deployments across the alliance.

Why This Article Matters (and Why You Should Bookmark It)

NATO conducts a rolling series of multinational exercises to sharpen collective defence across the alliance. For journalists, policy analysts, and security professionals, keeping track of these drills requires a single, up-to-date source.

This guide delivers exactly that: an evergreen reference you can rely on—continuously updated as new information emerges from NATO, SHAPE, or participating nations. No more digging through press releases or outdated PDFs.

Interactive Map: NATO Exercises in 2025

Zoom, click, or hover to explore the geographic distribution of this year’s drills.

Note: Marker positions are approximate mid-points of each exercise area.

2025 NATO Exercise Calendar at a Glance

Flagship Drills to Watch in 2025

Completed Highlights

DEFENDER EUROPE 25
Concluded in June, this trans-Atlantic logistics stress test successfully moved U.S. heavy forces to Europe and pushed them through Joint Reception, Staging, Onward Movement and Integration (JRSOI). NATO reported strong performance in contested-logistics scenarios, though bottlenecks at ports and rail hubs in Southern Europe highlighted enduring vulnerabilities.

ARCTIC CHALLENGE 25
Held in May–June, this was the first Arctic Challenge under full NATO membership of Finland and Sweden. Over 250 aircraft practiced cross-border air combat and agile basing. Analysts pointed to the exercise as a milestone in fusing Nordic defence cooperation with NATO’s High North posture.

FORMIDABLE SHIELD
May’s live-fire missile defence event in the Hebrides featured warships and aircraft intercepting ballistic- and cruise-missile surrogates. The exercise validated NATO’s growing Integrated Air & Missile Defence (IAMD) network, with AEGIS destroyers and European frigates successfully coordinating intercepts.

Current & Upcoming

NAMEJS 25 (8 Sep – 19 Oct, Latvia)
Latvia’s largest national defence drill, integrated into NATO’s command-post logic. The exercise is testing mobilisation, reserve integration, and alliance reinforcement in the Baltic under Article 5 conditions.

DYNAMIC MESSENGER 25 (Sep, Portugal / Atlantic)
NATO’s premier unmanned maritime experimentation exercise, focused on integrating naval drones and protecting undersea infrastructure. A forward-looking test of alliance readiness in the undersea and hybrid domain.

THUNDER STORM (10 – 31 Oct, Lithuania)
One of the autumn’s largest Article 5-oriented land drills, centred on reinforcing NATO’s eastern flank under high-intensity conditions. Expect robust allied participation and forward-deployed heavy forces.

MARE APERTO II (Oct, Italy)
A Mediterranean naval warfighting exercise pushing high-end fleet integration, including carrier strike groups and amphibious operations. It underscores NATO’s focus on stability in the southern flank while other attention is on the Baltic and Arctic.

Regional & Domain Hot-Spots

Northern Flank & Arctic Security

• Arctic Challenge 25 – Concluded in June; the largest Nordic air drill to date, now firmly integrated under NATO with Finland and Sweden as members.
• POLARIS 25 – Wrapped up mid-June; French-led naval and joint manoeuvres in the Atlantic, linked to High North readiness.
• Northern Coasts 25 – Completed in mid-September off Germany; naval forces rehearsed Arctic-Baltic security and critical sea-lane protection.
• Dynamic Messenger 25 – September, Portugal/Atlantic; NATO’s flagship unmanned maritime experimentation drill, testing drones and undersea infrastructure defence.

Baltic & Black Sea Deterrence

• BALTOPS 25 – Conducted in June; focused on naval manoeuvres in the Baltic Sea.
• Saber Guardian – Concluded in May across Bulgaria, Hungary, North Macedonia, and Romania.
• Breeze 25 – July drill in the Black Sea under Bulgarian lead.
• NAMEJS 25 – Running September–October in Latvia; the country’s largest national defence drill, integrated into NATO command structures.
• Thunder Storm – Upcoming in October, Lithuania; a large-scale Article 5 land exercise reinforcing NATO’s eastern flank.

Mediterranean & North Africa Stability

• African Lion – Completed in June, spanning Morocco, Senegal, Spain, and Tunisia.
• Mare Aperto II – Scheduled for October in Italy; high-end naval warfighting with carrier and amphibious components.
• Poseidon – October in Romania; mine counter-measures and Black Sea security focus.
• BULGARIA 2025 – Conducted 7–12 September; a civil-military emergency management exercise, underscoring NATO’s resilience agenda.

Rapid-Response & Airborne Readiness

• Swift Response 25 – Completed in May in the Balkans, testing airborne and rapid-deployment capabilities.
• Agile Spirit – Ran June–August in Georgia; land and joint drills under NATO partnership frameworks.

Frequently Asked Questions

What was the biggest NATO exercise in 2025?
DEFENDER EUROPE 25, held in June, was the largest by troop numbers and geographic spread—moving tens of thousands of personnel across multiple borders. No other 2025 drill matches its scale.

Are these drills offensive in nature?
NATO labels all 2025 exercises as defensive and deterrent. They are designed to improve the alliance’s ability to respond to crises under Article 5. This framing has been stressed repeatedly—especially in contrast to Russia’s Zapad 2025manoeuvres in September.

Will any exercises take place in the High North?
Yes. Earlier this year, Arctic Challenge 25 and Northern Coasts 25 both featured Arctic and Baltic operations. While those have now concluded, NATO has signalled that future iterations will expand as Finland and Sweden anchor the alliance’s High North posture.

How often is this guide updated?
We refresh the article whenever NATO or a host nation issues an official change—typically within 24 hours.
Last updated: 26 September 2025

How to Track Late‑Breaking Changes

1. Bookmark this guide—URL stays constant, content updates automatically.
2. Follow @Grosswald_org on X for instant headline alerts.
3. Opt‑in to our Großwald Curated newsletter (weekly, free) for a human‑curated recap of exercise highlights and geopolitical context.
4. Check NATO’s official newsroom for primary‑source press releases.

Further Reading

• Poland’s Homeland Defence Act 2025: NATO’s Eastern Anchor Becomes Operational
• Großwald Curated No. 23: Zapad 25 and NATO’s Eastern Flank
• NATO’s Five Percent Doctrine: Europe Defense Scenarios
• Russia’s Drone Incursions into Poland: NATO’s Eastern Sentry Signals
• Integrated Air & Missile Defense: Multilayer Architecture from SHORAD to Strategic Shielding

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