Russian harassment of NATO aircraft and escalation risk

Despite Russian Vladimir Putin’s assertion that Moscow is fighting a war against NATO in Ukraine—a claim clearly designed for a domestic audience—the Alliance, and presumably Russia, want to avoid a direct military conflict with one another. Nevertheless, a significant risk exists that the two parties could come into direct conflict as a result of inadvertent escalation. Inadvertent escalation occurs when intentional actions in a conflict situation have unintended escalatory effects as they cross a threshold that is important to the other side. This threshold may not be obvious or visible. It may result from one side not understanding—or misunderstanding—the other’s position, resolve to act in certain circumstances and in particular ways, or ‘incorrectly anticipating the second- or third-order consequences of the action in question’.¹ Escalation can also happen by accident. For example, this might result from one side attacking the wrong target because it has been misidentified, or a weapon system may fail mechanically, or because of a software problem, and in the process cause damage to an unintended target, cross a geographical boundary not by design, and so on.

There are different potential sources of escalation between Russia and NATO in the Ukraine context. Perhaps the most obvious and dangerous is framed by Russia’s activities in the air domain. Specifically, since February 2022, there have been several incidents of Russian aircraft interacting with and harassing NATO aircraft—both manned and unmanned—flying in proximity to Ukraine on intelligence gathering missions. Moscow self-declared an exclusion zone in the Black Sea at the start of its full-scale invasion of Ukraine which extends well beyond the 12 nautical miles off a country’s coastline, which is internationally recognized to be under sovereign control. NATO countries have not accepted Russia’s unilateral declaration of an exclusion zone. Russian aircraft had of course regularly shadowed NATO aircraft over the Black Sea for years prior to the war. NATO’s airborne intelligence gathering missions have provided the Ukrainian armed forces with real-time intelligence on Russian military activities. This has helped Ukraine prosecute its counter military campaign against Moscow’s unprovoked aggression, and informed NATO’s own understanding of the threat picture vis-à-vis the Alliance.

Two incidents in international air space over the Black Sea illustrate the risk of escalation, unintended or otherwise. On 29 September 2022, an unarmed Royal Air Force (RAF) RC-135W ‘Rivet Joint’ surveillance aircraft flying in international air space along a pre-declared route over the Black Sea in proximity to Crimea was, in the words of UK Defence Secretary Ben Wallace, ‘interacted with by two Russian armed Su-27 fighter aircraft’. In a statement to the House of Commons on 20 October—the first public recognition of the incident—Wallace revealed that, one of the Russian aircraft ‘released a missile in the vicinity of the RAF Rivet Joint aircraft beyond visual range’. The interaction time was ‘approximately 90 minutes.’ After the incident the UK communicated its concerns to Russian Defence Minister Sergei Shoigu about this ‘potentially dangerous engagement’ and suspended the patrols until it received a response. The Russian MOD responded on 10 October, claiming the incident was the result of ‘a technical malfunction of the Su-27 fighter’ and ‘acknowledged that the incident took place in international airspace’. The UK subsequently resumed the Rivet Joint patrols but with a fighter aircraft escort. It also informed the Russians about the escort ‘so there were no surprises.’ Wallace said that it was assessed that the incident on 29 September was not a deliberate escalation by Russia.²

In a New York Times article on 12 April 2023, two unnamed ‘U.S. defense officials’ speaking on the condition of anonymity said, ‘the Russian pilot had misinterpreted what a radar operator on the ground was saying to him and thought he had permission to fire. The pilot, who had locked on the British aircraft, fired, but the missile did not launch properly.’ The US officials said the ‘Rivet Joint was listening to intercepted communications between a Russian radar controller on the ground and one of the pilots of the Russian Su-27s dispatched to monitor the aircraft’.³

The second notable incident occurred more recently on 22 February 2023, when an unmanned American MQ-9 ‘Reaper’ surveillance drone flying in international airspace was intercepted, again by two Russian Su-27 fighter aircraft. Aviation fuel was dumped onto the unmanned air vehicle (UAV) and one Su-27 got close enough to clip the Reaper’s propeller, affecting its ability to fly, leading its controllers to ditch the vehicle in the Black Sea.⁴ On this occasion the US quickly released remarkable video footage of the actions of the Russian aircraft taken from the UAV itself. This left little room for Moscow to plausibly deny its aircraft were behaving recklessly. Indeed, the Reaper incident appeared to be deliberate and calculated on Russia’s part.

Such incidents demonstrate the risks associated with conducting military operations in contested airspace. But what do they tell us specifically about Russian intentions and more generally about escalation risk?

First, the Russians may be harassing NATO intelligence-gathering aircraft because they are providing Ukraine with data to assist its fight against Moscow. They may also be seeking to deter or limit NATO surveillance flights over the Black Sea by playing on Alliance concerns about escalation risk. Indeed, after the 29 September incident, the UK temporarily stopped its Rivet Joint aircraft flying missions. NATO’s unarmed surveillance aircraft are, of course, flying outside NATO airspace in proximity to Crimea, presenting Russian forces with one of their only opportunities to interact with Alliance aircraft. Doing so with armed aircraft fulfilling NATO’s air policing role could lead to a self-defence response, while Alliance aircraft involved in supplying security assistance to Ukraine will normally fly over NATO countries.

Second, there is clearly a difference in escalation terms between engaging in activity that leads to the loss of a UAV and the downing of a manned aircraft. The Reaper incident may have been the result of reckless flying by the Russian aircrew involved. But it may also be a demonstration of Russia’s willingness to interact more forcefully and kinetically with an unmanned system, because doing so does not come with the same escalation risk associated with potential or actual loss of life. By contrast, a Rivet Joint may have a crew of up to 30 personnel to effectively perform its functions.⁵

The hostile downing of an American drone is not a novel event. On 20 June 2019, an Iranian surface-to-air missile shot down a US RQ-4A ‘Global Hawk’ surveillance drone in what US CENTCOM stated was international air space, while the Iranians claimed otherwise.⁶ Although the US planned a retaliatory strike against Iranian radar and missile sites on 21 June, US President Donald Trump called it off shortly beforehand. In doing so, Trump Tweeted, ‘10 minutes before the strike I stopped it, not proportionate to shooting down an unmanned drone’.⁷ Did the lack of kinetic retaliatory action signal that the US would not respond to its drones being targeted in situations where it has a concern over escalation, thereby giving adversaries greater freedom to engage UAVs without fear of a significant response?

Third, the question then arises: to what extent might Russia be engaging in limited probes through its air interactions with NATO aircraft, manned or otherwise, to test the resolve of NATO members? Art and Greenhill describe a limited probe as a situation where ‘the challenger provokes a crisis to reveal the nature and extent of the defender’s commitment’ particularly if the challenger ‘believes the defender’s commitment is uncertain.’⁸

Fourth, the above incidents illustrate the importance of taking steps to reduce the chances of inadvertent escalation. In a 2008 RAND study, Morgan et al flagged three ways to do this: ‘working to recognize in advance the paths by which inadvertent escalation might occur in a particular situation’; ‘sensitizing leaders, strategists, and planners to the possibility and nature of inadvertent escalation in general and its potential risks in specific contingencies’; and ‘warning adversaries about inadvertent escalation risks they may not have recognized.’⁹ The relevance of these approaches was brought to sharp relief in Wallace’s remarks to the Commons on 20 October, when he said the Rivet Joint incident was ‘a reminder of quite how dangerous things can be when you choose to use your fighters in the manner in which the Russians have used them’. He further stated that, ‘We are dealing with a President and with Russian forces who, as we have seen from the Rivet Joint incident, are not beyond making the wrong calculation or deciding that the rules do not apply to them.’ All the more important in such circumstances then that the UK maintains, as Wallace emphasised, a ‘professional link with the Russian Ministry of Defence’ so there can be dialogue on ‘important engagements at times like this.’¹⁰

Concern for inadvertent and accidental escalation is not new. At the height of the Cold War in 1961, Schelling and Halperin wrote of the potential for inadvertent escalation stemming from ‘…unauthorized provocative action by a pilot or bomber or missile commander’.¹¹ In the same year, Snyder similarly wrote about the potential escalatory effect of ‘the inadvertent or irresponsible firing of a missile or dropping of a bomb’.¹²  These Cold War observations, and the recent incidents outlined above, illustrate that deliberate, accidental, and inadvertent moves by different sides in a contested environment could, in combination, create difficult to predict and cumulative escalatory dynamics. Different sides in a conflict may even present deliberate moves as accidental as a way to confuse and exacerbate the other’s sense of risk. Minimising the risks associated with escalation, therefore, requires a nuanced understanding of the challenger’s track record of behaviour and the prevailing set of conflict dynamics at any given time. It also demands constant attention to the requirements for both deterring deliberate escalation (escalation control), and the management of accidental and inadvertent escalation. Lessons will clearly have been drawn by NATO in this regard since Russia continued its aggression against Ukraine in February 2022. Scenario-based table-top exercises can also play an important role in training and educating personnel on escalation dynamics in specific contexts. This is not just relevant to NATO’s relationship with Russia. China’s provocative air operations around Taiwan demonstrate the importance of understanding the potential for cumulative escalatory dynamics in that context too.

Professor Wyn Bowen is the Co-Director of the Freeman Air and Space Institute (FASI). FASI provides independent and original research and analysis of air and space power issues. Based in the School of Security Studies, the Freeman Institute places a priority on identifying, developing and cultivating air and space thinkers in academia and industry, as well as informing and equipping air and space education provision at King’s and beyond.

1. Forrest E. Morgan, Karl P. Mueller, Evan S. Medeiros, Kevin L. Pollpeter, Roger Cliff, Dangerous Thresholds: Managing Escalation in the 21st Century, RAND 2008, p.23.

2. The Secretary of State for Defence (Mr Ben Wallace), ‘Ukraine Update’, House of Commons, Volume 720: debated on Thursday 20 October 2022, UK Parliament, Hansard, https://hansard.parliament.uk/ 

3. Thomas Gibbons-Neff and Eric Schmitt, ‘Miscommunication Nearly Led to Russian Jet Shooting Down British Spy Plane, U.S. Officials Say’, New York Times, 12 April 2023, https://www.nytimes.com/2023/04/12/world/europe/russian-jet-british-spy-plane.html?searchResultPosition=2 

4. Dan Lamothe, ‘U.S. says video shows Russia ‘flat-out lying’ about drone skirmish’, Washington Post, 16 March 2023, https://www.washingtonpost.com/national-security/2023/03/16/us-drone-video-russia/

5. Thomas Gibbons-Neff and Eric Schmitt, ‘Miscommunication Nearly Led to Russian Jet Shooting Down British Spy Plane, U.S. Officials Say’, New York Times, 12 April 2023, https://www.nytimes.com/2023/04/12/world/europe/russian-jet-british-spy-plane.html?searchResultPosition=2 

6. ‘Strait of Hormuz: US confirms drone shot down by Iran’, BBC, 20 June 2019, https://www.bbc.co.uk/news/world-middle-east-48700965 

7. US-Iran: Trump says military was 'cockedand loaded' to retaliate, BBC, 21 June 2019, https://www.bbc.co.uk/news/world-us-canada-48714414 

8. Robert J. Art and Kelly M. Greenhill, ‘Coercion: An Analytical Overview’, in Kelly M. Greenhill and Peter Krause (eds), Coercion: The Power to Hurt in International Politics (Oxford: OUP, 2018) p.11.

9. Forrest E. Morgan, Karl P. Mueller, Evan S. Medeiros, Kevin L. Pollpeter, Roger Cliff, Dangerous Thresholds: Managing Escalation in the 21st Century, RAND 2008, p.5.

10. The Secretary of State for Defence (Mr Ben Wallace), ‘Ukraine Update’, House of Commons, Volume 720: debated on Thursday 20 October 2022, UK Parliament, Hansard, https://hansard.parliament.uk/ 

11. Thomas C. Schelling and Mortin H. Halperin, Strategy and Arms Control (NY: Twentieth Century Fund, 1961), p.14. 

12. Glenn H. Snyder, Deterrence and Defense: Toward a Theory of National Security (Princeton, NJ: Princeton University Press, 1961, p.111.