NATO-Russia Weekly Briefing: September 20-26, 2025

Source: Compiled from public news sources and official communications. Date: September 27, 2025

This document summarizes the key events and official communications related to the NATO-Russia conflict for the week of September 20-26, 2025. The week was marked by a significant escalation in tensions, driven by a coordinated campaign of Russian hybrid warfare tactics. This campaign blended kinetic military provocations with disruptive cyberattacks against critical infrastructure, prompting a firm and unified response from the Alliance.

---

Key Daily Developments

• Friday, September 19 (Prior Week): The stage is set by a serious military provocation, as three armed Russian MiG-31 fighter jets violate Estonian airspace for over ten minutes before being intercepted by NATO aircraft.

• Saturday, September 20 - Sunday, September 21: The weekend sees heightened rhetoric. Pro-Russian hacktivist groups begin signaling coordinated cyber operations against European transportation infrastructure.

• Monday, September 22: A major hybrid attack unfolds in Denmark. Unidentified surveillance drones force a four-hour shutdown of Copenhagen’s Kastrup Airport, disrupting travel for 20,000 passengers. Simultaneously, the airport’s website and flight information systems are targeted by DDoS attacks, and a ransomware attack (believed to be HardBit) targets the MUSE check-in and baggage handling software used at Copenhagen and other European airports, including London Heathrow and Berlin Brandenburg. Danish officials label the events a “hybrid attack” and the “most serious attack on Danish critical infrastructure to date.”

• Tuesday, September 23: The North Atlantic Council meets under Article 4 of the Washington Treaty. The Council’s statement strongly condemns the violation of Estonian airspace and the “coordinated cyber and physical attacks” on Danish critical infrastructure, declaring that NATO will use “all necessary military and non-military tools to defend itself.”

• Wednesday, September 24: Debris from a Russian drone is discovered in Romania near the Ukrainian border. The Finnish OSCE Chairpersonship convenes a joint meeting to address the pattern of airspace violations and hybrid attacks.

• Thursday, September 25: Russian Foreign Minister Sergey Lavrov delivers a speech accusing NATO and the EU of having “declared war” on Russia.

• Friday, September 26: The NATO Military Committee convenes in Riga, Latvia, to discuss the implementation of new regional defense plans and the “Eastern Sentry” initiative. Drone sightings and minor cyber disruptions continue to cause intermittent delays at Aalborg Airport in Denmark.

---

Overall Context in September 2025

This week’s events demonstrate a clear and coordinated Russian hybrid warfare campaign. The use of military aircraft in Estonia, surveillance drones to disrupt civilian air travel in Denmark, and drone debris falling on Romania are not isolated incidents. They were synchronized with cyberattacks on the same critical infrastructure, designed to maximize disruption and sow public fear. This represents a deliberate strategy to test NATO’s resolve, cohesion, and response times across both the physical and digital domains. NATO’s reaction—combining firm public condemnation (Article 4) with concrete military reinforcement (“Eastern Sentry”) and new initiatives (the “drone wall”)—shows a determination to present a united and credible deterrent to this evolving, multi-faceted threat.