Baltic Security: SITREP

The Baltic states of Estonia, Latvia and Lithuania, which remain the most vulnerable NATO members on the Alliance’s Eastern Flank, closely monitor international developments in their region. The latest series of incidents has forced NATO to increase its presence and commitment along its Eastern Flank.

One moment of heightened concern came in mid-September with the Russian-Belarusian military exercise ‘Zapad’ (ENG: West), held regularly every 2–4 years since the late 1990s. These exercises consistently rehearse hostile scenarios against NATO members. This year’s drills included simulated attacks on key NATO areas, notably the Suwałki Gap – the narrow stretch of territory between Poland and Lithuania that separates Belarus from Russia’s Kaliningrad exclave. The last iteration, in September 2021, ended with Russian troops not returning to their barracks but instead preparing for the full-scale invasion of Ukraine early the following year.

Ultimately, the drills turned out to be relatively modest, with no serious provocations reported. This year, approximately 30,000 soldiers participated. Colonel Ants Kiviselg, head of the Estonian Military Intelligence Center, assessed that this year’s edition of the exercises was 10 to 20 times smaller than those held in 2017 and 2021. The only notable act of psychological warfare was the release of a video showing a nuclear-capable Iskander missile system traveling on a road leading from Kaliningrad toward Poland.

In response, Poland and Lithuania conducted their own manoeuvres, including Iron Defender 25 and Thunder Strike, both with the participation of NATO allies. Iron Defender 25 took place on land, air, and sea in the Baltic, involving about 30,000 troops from Poland and other NATO states. Thunder Strike brought together 17,000 troops in Lithuania as part of the broader Iron Defender exercise, organised by the United States European Command spanning Estonia, Latvia, and Lithuania, and Poland. The Quadriga 2025 exercise, held in the Baltic Sea, involved around 8,000 personnel from 14 NATO member countries, with the main goal being to improve NATO’s ability to quickly reinforce Estonia, Latvia, and Lithuania if needed.

Escalating tensions

The crisis on NATO’s Eastern Flank, closely monitored by the Baltic states, deepened further on the night of 9-10 September, when about 20 Russian drones violated Polish airspace. The incursion formed part of a broader, large-scale attack on Ukraine. Polish F-16s, supported by Dutch F-35s, intercepted and destroyed several Russian Gerbera drones. Both Poland and Lithuania had earlier been warned by Belarus about the possibility of drone incursions.

In July 2025, two light drones (one armed with 2 kg of explosives) crossed into Lithuanian airspace, with one crashing at the Gaižiūnai training ground in Jonava District; both drones were launched from Belarus. In response, Lithuania announced plans to improve information-sharing, communication channels, and response times between institutions, security services, and the military, to better address such threats in the future.

Incidents continued to multiply across the region. In September 2024, an explosive-laden Shahed-type drone crashed in Latvia, while several Ukrainian drones accidentally came down in Estonia. A year later, on 8 September 2025, a Russian Mi-8 helicopter with its transponder switched off, entered Estonian airspace over the Baltic Sea, remaining there for four minutes. As a consequence, both Latvia and Lithuania introduced new airspace restrictions along their eastern borders from 11-18 September. Then on 19 September 2025, three Russian MiG-31 aircraft violated Estonian airspace for around 12 minutes.

A more troubling development came on the night of 9-10 September 2025, when at least 21 Russian Geran one-way attack (OWA) drones or Gerbera decoys violated Polish airspace, with one crashing into a house. In response, Poland invoked Article 4 of the Washington Treaty and requested consultations with its allies. NATO subsequently launched Operation Eastern Sentry along the Alliance’s Eastern Flank. The mission will be coordinated by NATO’s Allied Command Operations (ACO) and is modelled on Operation Baltic Sentry, introduced in January 2025 to strengthen security in the Baltic Sea.

“I don’t know if the Russians planned it this way, but they did us a favour by drawing NATO’s full attention to our region and its threats,” commented Lithuanian President Gitanas Nausėda. He added that Operation Eastern Sentry is “very good, because it will allow us to fill certain gaps in our air defence, with the help of our allies”. The operation involves contributions from several NATO members: Denmark (two F-16s and an anti-air warfare frigate), Germany (four Eurofighter jets), France (three Rafales), and most likely also the United Kingdom.

At the same time, the Baltic region continues to grapple with the problem of illegal migration, orchestrated by Russia and directed through Belarus toward the EU’s eastern border. In response, the Baltic countries have erected border fences to contain the problem. However, attempts to cross have continued and border guards operating along the Belarusian border have even faced sporadic attacks over the last few years. Between January and July 2025, Lithuanian border guards prevented 917 irregular migrants from crossing through non-designated areas along the Belarusian frontier. During the same period, Poland blocked 15,213 attempts, while Latvia reported 6,078. According to Lithuanian media outlet LRT, “since the start of the migration crisis caused by Belarus in summer 2021, more than 180,000 unauthorised entries into Lithuania, Poland, and Latvia have been prevented”.

For the Baltic states, relations with Belarus remain a key concern. The country continues to act as a Russian satellite, implementing the Kremlin’s strategic objectives aimed directly against NATO. Hopes for any normalisation of ties with Minsk are limited, given Belarus’s deep dependence on Moscow. Nonetheless, signals occasionally emerge from President Alexander Lukashenko’s regime suggesting a willingness to improve relations. One such signal appeared in mid-September 2025, when Donald Trump’s envoy, John Cole, visited Minsk. As a direct result of the talks, the regime released 52 political prisoners, and the US lifted sanctions on the Belarusian airline Belavia. Other states in the region, however, view these developments with suspicion, interpreting them as propaganda moves aimed at weakening the White House’s determination to confront the Belarus–Russia axis.

National initiatives

In the face of persistently high tensions, compounded by uncertainty about Russia’s future intentions, the Baltic states are systematically modernising their armed forces and initiating programmes to strengthen infrastructure. To bolster their defence capabilities, all three countries have significantly increased military spending and intensified joint exercises, both at the staff level and in field training. Lithuania is allocating 4% of its GDP to defence this year (up to USD 3.3 billion) and has committed to increasing defence spending to 5-6% of GDP between 2026 and 2030. One of the key reasons behind this decision is the plan to establish a new division, expected to reach operational readiness by 2030. It will have tanks, wheeled and tracked IFVs. Latvia plans to spend 3.45% of its GDP on defence in 2025 (USD 1.5 billion) and 3.73% of GDP in 2026. Estonia, which faces the highest level of exposure, has earmarked 3.3% of its GDP (USD 1.3 billion) for defence, with a government commitment to allocate USD 5.6 billion over the next four years for this purpose.

 

A key measure remains the construction of fortifications along the eastern border to delay any potential Russian assault. This project is known as the Baltic Defence Line. The decision was made by all three states in January 2024, although they had already undertaken certain steps earlier on. These efforts were not driven solely by the spectre of war with Russia but also served as a response to migration pressure. The specific details of the Baltic Defence Line have not been disclosed, but it is known to include defensive positions for troops, fortified structures, various obstacles, anti-tank ditches, and ammunition and mine depots. Natural barriers such as forests, rivers, and lakes will also be integrated into the defence system. It is expected to be linked with Poland’s Eastern Shield.

At the same time, the Baltic states are strengthening their non-military security as well. For instance, in February 2025, thanks to an EU programme covering 75% of costs (USD 1.2 billion), the process of synchronising the Baltic states’ power grids with European networks was completed. Just a day earlier, they had been disconnected from the BRELL grid managed by Russia. This step increases the integration of the Baltic states with the West while simultaneously reducing their vulnerability to Russian pressure.

The countries of the region are counting on even greater support from their NATO allies. For instance, in August 2025 Lithuanian Defence Minister Dovilė Šakalienė urged NATO to strengthen its air defence on the Eastern Flank, while in September Latvian President Edgars Rinkēvičs stated that, due to the deteriorating security situation in the region, NATO should accelerate the establishment of the Baltic Air Defense Mission. Lithuania, for its part, plans to purchase additional air defence capabilities worth USD 500 million.

However, concerns in the Baltic states have recently grown significantly following reports in early September that the United States would no longer finance the Baltic Security Initiative (BSI). This programme, launched in 2020, is designed to support the development of defence capabilities in Estonia, Latvia, and Lithuania. Already approved funds will remain available until the end of September 2026, though some changes are still expected. A day after Poland intercepted several Russian drones, lawmakers from Estonia, Latvia, and Lithuania sent a joint letter to the US Congress, urging Washington to continue military assistance under the BSI framework. However, it should be noted that the BSI programme provided only a portion of US funding for strengthening the Baltic states’ defence capabilities. The key element remains the EDI (European Defence Initiative), which provides, among other things, funding for the rotational presence of US ground forces on the Eastern Flank.

 

Robert Czulda