Sep 21, 2023
Russian President Vladimir Putin's invasion of Ukraine in February 2022 has imposed devastating losses on the Russian military and on Ukraine's military and civilian populations, but both sides have avoided certain escalatory options. Putin has been restrained for several reasons, including fear of NATO's military response; an information flow that filters out negative facts, promoting the view that Russia can win a protracted war; and incremental increases in NATO support for Ukraine.
The fact that Putin has avoided certain escalatory options to date does not mean that he will avoid them in the future. The Kremlin's control of Russia has become brittle, potentially encouraging Putin to consider options to shorten the war. Withdrawal from Ukraine is one such option. Greater escalation is another, including attacking NATO directly, intensifying the use of Russian air forces against Ukraine, and using chemical weapons. Putin could also use nuclear weapons inside Ukraine. The risks to the Kremlin would be enormous, but a sudden deterioration of Russian forces or threats to internal stability could lead Putin to view nuclear weapons as the best among a set of bad options. Should he choose to take that risk, he may not be restrained in the number or types of weapons he uses inside Ukraine.
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Russia's invasion of Ukraine in February 2022 has imposed devastating losses on both the Russian military and Ukraine's military and civilian populations. But to date, both sides have avoided certain escalatory options. Russian President Vladimir Putin has not broadened the conflict by attacking the United States or other NATO members to punish them for supporting Ukraine. He has also not pursued certain escalation options against Ukraine—most notably, the use of nuclear weapons.
Russia's decision calculus about escalation was, not surprisingly, the focus of prewar analyses by the United States and NATO. However, events in the past year have proven those analyses wrong. Putin has proven to be more hesitant to escalate, particularly against NATO, than was generally assumed before the war, and how escalation decisions appear to be made in Russia differs from prewar expectations, with Putin making key decisions largely on his own without substantial influence from the Russian General Staff. However, the fact that Putin has avoided certain escalatory options to date does not mean he will avoid them in the future. If Russian territorial, personnel, and materiel losses continue to mount without improvements on the battlefield, he will face a set of unpalatable choices, including negotiations from a position of weakness, more-extensive and potentially destabilizing mobilizations, or more draconian attempts to ensure internal control. A changing environment may prompt him to rethink the risk calculation, making escalation preferable to other options.
To explore the multiple dimensions of escalation in the war in Ukraine, the RAND research team posed three main questions.
Previous RAND researchers defined escalation as an increase in the intensity or scope of a military conflict “that crosses threshold(s) considered significant by one or more of the participants.” It can be vertical (i.e., changes in the intensity of conflict) or horizontal (i.e., changes in the geographic scope of conflict). Escalation can be deliberate, inadvertent, or accidental (see Table 1).
The risks of accidental escalation are likely to persist for the duration of the conflict. However, it is difficult to predict when or how accidental escalation might occur. This analysis focuses on risks of inadvertent and deliberate escalation.
|Type of Escalation
One side escalates purposefully to prevent defeat or gain an operational advantage
A state decides to use nuclear weapons to eliminate a conventional capability of its adversary
One side takes an action it does not perceive as escalatory but its opponent interprets it as such
A state undertakes a conventional strike that inadvertently damages its adversary's nuclear command and control systems; the adversary interprets this action as intentional targeting of these systems
Unintended action or mistake
A communications failure in a nuclear missile silo leads to a launch that was not authorized by the state's leadership
Assumptions of U.S. analysts about how and why Russia would consider escalation have proven inaccurate for two reasons: (1) misunderstanding how strategic decisions in Russia are actually made and (2) substantially misreading Russian risk tolerance and willingness to militarily confront NATO. As one expert pointed out, Putin was treated “as a rational thinker with good information.” In reality, Putin overemphasized secrecy in planning the invasion, overestimated the quality of his plan and prospects for success, and underestimated both Ukrainian will and Western cohesiveness.
Strategic misjudgment and poor invasion planning. Putin's miscalculations created situations for which he and his advisers were unprepared.They believed they could seize Kiev quickly,rendering NATO promises to provide Ukraine with support basically irrelevant. NATO cohesion appeared mixed before the invasion, but Russia's brazen invasion and ruthless prosecution of the campaign brought about a sea change in European political and strategic calculations. In this changed environment, Russia has seemed uncertain about how to deter NATO from providing this assistance.
Misperceptions about Ukrainian capabilities and will to fight. The ease with which Putin seized Crimea in 2014 led him to assume that capturing the remainder of Ukraine would be comparably easy: Russia would be confronting the same corrupt, effectively leaderless entity it encountered in early 2014. Putin missed signs of Ukraine's democratic political development over the previous eight years, the growth of a cohesive national identity, and substantial investments in Ukraine's military capabilities.
These misperceptions led Putin to conclude that he did not need to plan for escalation. When battlefield reversals could not be denied, he attacked Ukraine's civilian population and critical infrastructure, again misjudging Ukrainian resolve.
Misperceptions about European politics and Western unity. Putin believed that the Western alliance could be fractured if appropriate threats and pressure were applied, including shutting off natural gas exports to Europe . He misperceived the latent degree of allied political and diplomatic unity, failing to recognize that unity would be enhanced by the experience of observing Russia's brutal conduct in the war. At least initially, he may have believed that limited horizontal escalation efforts could work, curtailing NATO assistance to Ukraine without taking further risks.
Russian tolerance of NATO assistance to Ukraine.The West underestimated Russia's fear of NATO and accompanying hesitance to confront NATO directly.
Overestimation of the effectiveness of Russian escalatory tools and options.In addition, battlefield losses and depletion of weapons stockpiles have left Russian leaders with a more limited set of escalation tools. Attempts to starve and freeze populations by withholding energy and food resources or attacking critical infrastructure failed to change European or Ukrainian behavior.
Russia's insular decisionmaking.Putin and his inner circle appear to have made little use of economic or military expertise in their “shambolic plan for invasion,” as one expert described. Putin has narrowed the funnel of information that reaches him to exclude the diplomats, economic ministers, and others who might have offered contrary advice; increasingly, he makes his decisions in isolation. Crises also appear to have affected him personally, adding emotion and anger to an already insular decisionmaking process.
The two most significant examples of Russian escalation involved attacking Ukraine's civilian population and targeting critical infrastructure. Russia has made no sustained effort to interdict NATO support efforts in Ukraine.
Why has Russia not escalated more? Russia's fear of NATO encourages the Kremlin to behave cautiously rather than risk direct conflict. In addition, the information flow in the Russian system filters out negative facts, promoting the view that Russia's prospects for winning a protracted war are still high. Russian incentives to escalate may also have been diminished because support to Ukraine has increased gradually. No single change in assistance was sufficiently dramatic to risk war with NATO to prevent it.
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The ongoing war carries with it risks of inadvertent escalation that have yet to materialize. To better appreciate these risks, we outline three horizontal escalation scenarios that are plausible based on what we know of Russian,Ukrainian, and NATO activities to date.
Through these or other scenarios, the potential for inadvertent escalation is likely to persist for the duration of the conflict, highlighting the value of maintaining open lines of military and diplomatic communications with Russia to help disrupt such spirals.
The potential for inadvertent escalation is likely to persist for the duration of the conflict, highlighting the value of maintaining open lines of military and diplomatic communications with Russia to help disrupt such spirals.
However, it is deliberate escalation decisions that pose the greatest risk. Putin appears to believe that a war of attrition will eventually fracture either Ukrainian capabilities and will or diminish Western support for Kyiv. However, near-term prospects for either outcome are diminishing. The commitment of resources to invading Ukraine has left the Kremlin’s control of Russia itself brittle, potentially reducing its appetite for a protracted war of attrition and encouraging options to shorten it. Withdrawal from Ukraine is one such option. Greater deliberate escalation is another.
The research team identified options for deliberate escalation that Russia or Ukraine could pursue (see Table 2). Russia remains the actor with the greatest potential to deliberately escalate the conflict, but Ukraine also has motivation and some capabilities to escalate. For each escalation option, the team identified the likely motivations that could prompt the country to take this step, assessed whether it has the capabilities to take the step as of summer 2023, and identified restraining factors that may have so far inhibited Moscow or Kiev.
|Ability to Execute
Limited Russian attack against NATO in Europe
Coerce NATO to limit or cease support to Ukraine
Varies depending on scale and nature of attack
Russia Provokes out-of-area crisis
Distract U.S. and allies to reduce support for Ukraine
Challenging to incentivize a state to provoke a crisis unless it was already predisposed
Russia conducts large-scale air and missile campaign against Ukraine
Establish some measure of air superiority in skies over Ukraine
Russia may incur serious losses to destroy Ukrainian air defenses but may be able to achieve air superiority
Russia initiates large-scale use of chemical weapons in Ukraine
Battlefield advantage; break Ukrainian civilian and military morale; motivate NATO members to push Ukraine to negotiations
Size and scope of chemical weapons arsenal unclear; logistical challenges in employment
Russia conducts underground nuclear test
Signal to NATO that continued support risks escalation; threat to nonproliferation efforts to use as leverage
Russia likely has capability to conduct nuclear tests
Russia uses nuclear weapons inside Ukraine
Prevent rapid catastrophic Russian battlefield losses that could threaten regime; coerce NATO to push for a ceasefire
Extensive Russian nuclear capabilities; however, tactical weapons kept at lower readiness levels, and Russian ground forces likely ill prepared to operate on nuclear battlefield
|Option G. Ukraine expands its strikes inside Russia
Increase domestic political costs for Russian leadership, hamper Russia's military activities by striking logistics or command and control centers
Some demonstrated capability to execute unmanned aircraft system strikes. Expanding campaign likely possible if willing to accept losses, trade-offs with frontline operations
NOTE: PRC = People’s Republic of China.
Both Russia and Ukraine have additional escalation options. Figure 1 illustrates how the risk of different options may vary depending on the trajectory of the war. The horizontal axis of the figure shows the challenges that Russia or Ukraine would face in executing each option, with more-executable options to the left and less-executable options to the right. The vertical axis shows the likely degree of Russian or Ukrainian hesitancy to attempt the option, given both motivations and restraining factors. Taking these two dimensions together, options that are closer to the bottom left of the figure are those most likely to occur. Although illustrative, Figure 1 shows how a dramatic shift in battlefield conditions—in this case, an imminent Russian military collapse that threatens the survival of the current Russian regime—could alter the likelihood of different escalation options. In the event of such collapse, several highly destructive escalation options, including nuclear use inside Ukraine, would become more likely.
Any assessment of the risk of Russian escalation should be approached with humility. Russian behavior to date does not provide definitive information about future Russian escalation decisions: The circumstances that could prompt escalation in the future may not be ones that the Russian leadership has previously faced. Nonetheless, we can learn from Russian behavior in the conflict to date.
Russia and the West both entered the early stages of the war with several misperceptions and faulty assumptions. Because Russia overestimated its own capabilities and prospects for success while underestimating Ukrainian will to resist and NATO cohesion, it devoted little effort to developing viable escalatory strategies. However, Russia has since improvised several escalatory actions, including shutting off gas exports to Europe and expanding missile strikes inside Ukraine. These efforts reflect a Kremlin exploring and testing reactions to different escalation options.
What has restrained Russia from going further? A fundamental factor appears to be an acute fear of NATO's military capabilities. Russia also remains sensitive to international relations, at least with more established partners, such as the People's Republic of China. But Russia's belief that it can still win a war of attrition is likely also key. As long as Russia can endure its own extensive costs, and its domestic challenges do not increase, Putin may cling to the belief that he will eventually prevail without taking further risks.
This calculus could change if Russia decides that escalation is required to protect the regime's survival.
Ukraine also has both the motivation and at least limited potential to escalate the conflict by undertaking more sustained strikes inside Russia. But thus far, Ukrainian escalation in this area has been limited by the enormous operational demands of expelling Russian forces from their territory, and likely to a lesser extent by its promises not to use NATO-supplied military capabilities to attack inside Russia. However, should Ukraine decide that greater strikes inside Russia are necessary to win the war or avoid defeat, NATO pressure or prior promises may not deter them.
Russian nuclear escalation options against Ukraine may become more attractive to Putin and his inner circle if they perceive a threat to regime security. Technical and operational issues impose a very high bar for battlefield nuclear use in Ukraine. But in an effort to coerce NATO to push Ukraine to a ceasefire, Russia could use nuclear weapons to signal to Ukraine and NATO that the risks of escalation to general nuclear war have become acute if the battlefield situation is not stabilized.
It is uncertain whether that tactic would achieve the desired operational or psychological impact, and the risks to the Kremlin from using nuclear weapons would be enormous. But a sudden deterioration of Russian forces in Ukraine or sharp increase in threats to internal stability could lead the Kremlin to view nuclear use as the best of a series of bad options.
Should Russia decide to use nuclear weapons inside Ukraine, it may not be restrained in the number or types of weapons it employs there. Russia's leadership may perceive that the costs and risks of using only a few or only small nuclear weapons are not dramatically different from those associated with using more or larger weapons, particularly if the Kremlin believed that the latter would achieve Russian battlefield objectives while the former may not.
This assessment of escalation risks in the war in Ukraine highlights implications for U.S. and NATO policymakers, underscoring several critical trade-offs.
Examination of Russia’s escalatory behavior and future options in Ukraine suggests implications for policymakers as they consider future crises and conflicts, particularly those involving nuclear-armed states where the United States would be concerned about potential nuclear escalation risks.
An end to the war in Ukraine without substantially greater escalation should not necessarily hearten policymakers and military planners as they consider risks in other conflicts. However, greater escalation in Ukraine despite mitigating factors would underscore the likely risks in other contexts, reinforcing the need for policymakers to confront and plan for those risks before any future conflict with a nuclear-armed adversary.