Switzerland Signs Agreement to Acquire IRIS-T SLM Air Defense Systems

Switzerland has formally entered into a cooperative defense procurement agreement with Germany to acquire IRIS-T SLM medium-range ground-based air defense (GBAD MR) systems. This move aligns the country with the European Sky Shield Initiative (ESSI), a multinational framework launched in 2022 to enhance air defense coordination and interoperability across Europe. The agreement, signed by Swiss Armaments Director Urs Loher and German National Armaments Director Vice Admiral Carsten Stawitzki, was approved by the Swiss Federal Council on June 20, 2025, and is expected to culminate in a procurement contract during the third quarter of 2025.

IRIS-T. Diehl Defence

The IRIS-T SLM system, developed by Germany’s Diehl Defence GmbH & Co. KG, is designed to provide medium-range air defense capabilities against a spectrum of aerial threats, including cruise missiles and stand-off munitions. Switzerland plans to procure five such systems, supported by a previously approved guarantee credit of 660 million Swiss Francs under the 2024 armament program. The system integrates a launcher unit with multifunction radar, notably the TRML-4D, and is intended to serve as the backbone of Switzerland’s mid-range air defense under the ESSI framework.

The strategic rationale behind this procurement is multifaceted. First, it addresses existing capability gaps in Switzerland’s air defense architecture, particularly in the medium-range domain. Current systems such as the Stinger and medium anti-aircraft artillery are increasingly seen as inadequate in countering modern aerial threats that operate at higher altitudes and longer ranges. The IRIS-T SLM is expected to complement existing long-range systems like the Patriot missile system, thereby reinforcing a layered defense structure.

Second, the joint procurement under ESSI offers potential cost efficiencies through economies of scale and shared technical standards. This cooperative model is designed to enhance interoperability among participating nations while allowing each country to retain operational autonomy. In Switzerland’s case, the agreement explicitly states that the systems will be operated independently, without integration into NATO or German command structures, thereby maintaining compliance with Swiss neutrality laws.

The ESSI itself represents a broader European effort to consolidate air defense capabilities in response to evolving security dynamics. The initiative was conceived in the context of increased awareness of aerial threats, particularly following Russia’s continued missile and drone attacks on Ukrainian cities. Switzerland’s participation, formalized in October 2024, includes not only joint procurement but also collaboration in training, maintenance, and logistics.

From a policy perspective, the acquisition aligns with the Swiss Federal Council’s Armament Policy Strategy, which emphasizes modernization, interoperability, and strategic autonomy. The decision to procure the IRIS-T SLM systems is positioned as a step toward regaining geospatial cruise missile defense capabilities and expanding coverage across lower, medium, and parts of upper airspace. This is seen as essential for maintaining air sovereignty and ensuring freedom of action within an integrated air defense framework.

Switzerland’s decision to join the European Sky Shield Initiative and procure IRIS-T SLM systems reflects a calculated approach to modernizing its air defense infrastructure. The move is grounded in strategic, operational, and economic considerations, and is structured to preserve national autonomy while contributing to a broader European security architecture. The forthcoming contract, expected to be finalized in summer 2025, will mark a significant milestone in Switzerland’s defense posture and its engagement in multinational defense cooperation.

The IRIS-T SLM’s technical architecture is a key factor in its growing adoption across Europe. The system is built around a modular and scalable design, allowing for integration with a variety of radar and command-and-control platforms. This flexibility enables tailored configurations based on national requirements and terrain-specific constraints. The missile itself features a vertical launch capability, providing 360-degree engagement coverage. It can intercept targets at ranges up to 40 kilometers and altitudes reaching 20 kilometers, making it suitable for defending against a wide array of threats, including fast-moving aircraft, cruise missiles, and unmanned aerial vehicles.

The guidance system of the IRIS-T SLM combines inertial navigation, GPS updates, and a terminal imaging infrared seeker. This multi-layered approach enhances accuracy and resilience against electronic countermeasures. The missile’s high agility and precision are further supported by thrust vector control and advanced image processing algorithms. These capabilities have been validated in operational environments, most notably in Ukraine, where the system has demonstrated a high success rate in intercepting incoming threats under combat conditions.

Operational deployment of the IRIS-T SLM typically involves a battery configuration that includes multiple launchers, a radar unit—often the TRML-4D multifunction radar—and a command post. The TRML-4D radar provides rapid target acquisition and tracking, supporting simultaneous engagement of multiple threats. This configuration allows for both stationary and mobile deployment, enhancing the system’s tactical versatility.

Switzerland’s procurement of the IRIS-T SLM is part of a broader trend among European nations seeking to modernize their air defense capabilities. Countries such as Sweden, Estonia, and Latvia have also placed orders for the system, citing its proven performance and interoperability within the ESSI framework. These acquisitions reflect a collective shift toward integrated and layered air defense strategies in response to the evolving threat landscape.

The decision to adopt the IRIS-T SLM also carries implications for defense industrial cooperation. By aligning procurement with other ESSI participants, Switzerland positions itself to benefit from shared logistics, joint training programs, and coordinated maintenance cycles. This approach not only reduces long-term operational costs but also fosters strategic alignment with neighboring countries without compromising national sovereignty.

The IRIS-T SLM represents a significant advancement in medium-range air defense technology. Its adoption by Switzerland under the ESSI framework underscores a pragmatic approach to national defense—one that balances technological capability, strategic autonomy, and regional cooperation. As the security environment in Europe continues to evolve, systems like the IRIS-T SLM are likely to play a central role in shaping the continent’s collective defense posture.