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Arctic Matryoshka: Russia’s Multi-Layered “Bastion Defence” in the 21st Century

Russia's revival of the "bastion defence" concept in the Arctic raises challenges to NATO.

A bastion is a projecting part of a fortification that enables the defending force to eliminate the “dead space” immediately below the parapet of traditionally linear medieval fortress walls. Usually located at the corners of a fortification, bastions thus increase defensive combat effectiveness. Although bastions increasingly grew obsolete due to their physical immobility coupled with the advent of tanks and military aviation, the bastion as a concept remains to this day.

Under President Vladimir Putin, the Arctic has experienced a renaissance in geopolitical attention, reflected in the revival of over 50 Soviet-era military bases above the Arctic Circle. Geostrategically, after being dormant following the collapse of the Soviet Union, the Russian Federation has revived its “bastion defence” concept in the Arctic. In this analogy, the bastion’s main objective is securing the perimeter around the Kola Peninsula, which hosts Russia's Northern Fleet. Ensuring the survivability of its fleet of eleven nuclear-powered ballistic missile submarines (SSBNs) is vital to maintaining credible deterrence. The Kola Peninsula represents the fortress.

The actual bastion - the projecting part of the fortification - is made up of multi-layered air defence systems and domain awareness activities. On the one hand, a network of modernized and advanced short-, medium-, and long-range air defence systems contributes to anti-access / area-denial (A2/AD) efforts. On the other hand, regularly scheduled strategic submarine and long-range aviation patrols boost domain awareness in the region and conventional deterrence. For example, on April 3, two Tu-95MS strategic missile-carrier bombers, accompanied by at least one Su-35S fighter jet, performed a patrol along NATO airspace over the Norwegian and Barents Sea. Occasionally, A-50 reconnaissance aircraft tag along to perform cartographic tasks and signal intelligence.

Whereas Russia seeks to exert control within the boundaries of its bastion, the goal in the Norwegian Sea is area denial or bastion defence. The concept thus reaches as far as the Greenland-Iceland-United-Kingdom (GIUK) gap in the southwest. It is reported that the frequency of Russian submarine patrols in that area has reached Cold War Levels. It should be noted, however, that an increase in domain awareness activities does not equal malicious intent. In fact, Traditionally, these defensive measures are seen by the West as “legitimate interests in national defence.” 

Nevertheless, Russia is employing a “double dual” strategy, whereby dual-use infrastructure, like harbours or airports, are used for dual purposes, i.e. civilian and military reasons. This means that Russian military capabilities deliberately keep the offensive-defensive distinction vague. The second objective of the bastion concept is to guarantee access to the Northern Atlantic through the GIUK gap. This is especially concerning for NATO. If a large-scale military confrontation were to occur, Allied reinforcement would depend on the transatlantic sea lines of communication (SLOC). Similar to the German strategy in World War II, Russia could seek to interdict supply lines.

In order to prevent such a strategic nightmare, NATO must ensure robust transatlantic SLOC. Allies have realized that improvements in ageing intelligence, surveillance and reconnaissance (ISR) capabilities were long overdue and have started to abandon their reluctance to invest. In addition, NATO must double down on its anti-submarine warfare (ASW) capabilities in the North Atlantic and GIUK gap. It cannot afford to lose to increasingly stealthy Russian submarines. Western intelligence services sharpen their warnings that Russia is planning a large-scale conventional conflict with NATO. As legitimate as Russian defensive capabilities may be, NATO must be capable of averting potential Russian subversive actions in the North Atlantic to guarantee the survival of the transatlantic corridor.


Malte Koppermann

Malte Koppermann has recently completed his BSc in International Relations and Organizations at Leiden University. In the third year, he completed a minor in Cyber Security and wrote his thesis on how sea-based colonial violence in pre-partition Samoa alters our understanding of territorial sovereignty in Historical IR. Currently, he posts daily updates on the war in Ukraine on X and is interested in OSINT, international security and history. Later this year, he intends to start his graduate degree in Intelligence.


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