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Using Cross-Domain Deterrence to Understand the Ukraine Crisis

****This post was authored by IGCC visiting scholar and professor of political science at the US Air Force Academy, Dr. Damon Coletta****

The recent sequence of challenges and deterrence threats over the political future of Ukraine may be analyzed using the concepts of cross-domain deterrence.  The notion of threat and response playing out over multiple chessboards helps policy makers evaluate the limited strategic disruption from a challenge that made some headway against the status quo in a large, important state like Ukraine.  The absence of great power war, or even mobilization for major war, may indicate a remarkable shift in power politics behavior previously entrenched through the widely perceived success of classical, twentieth-century deterrence.

During the Cold War, superpowers faced each other as scorpions in a bottle, trapped by the unprecedented destructive power of nuclear arsenals.  Heads of state for both parties openly acknowledged that an all-out attack using thousands or even hundreds of megaton warheads would be disastrous for all sides.  Both the Soviet Union and the United States had secure second-strike capability; like the scorpions they would deliver a mortal blow to their rival even as the life force ebbed from their own body politic after absorbing a first launch.  In game theory terms, nuclear deterrence resembled the payoffs of Chicken with two symmetric equilibria having exactly the opposite political consequences:  either the USSR or the USA would demand surrender and the other side, perhaps the status quo player of the game, would have no other rational move except to grant it.

Thomas Schelling clarified what this meant in his famous works from the 1960s.  Not wanting to be taken advantage of, both superpowers would have an incentive to search for openings, to see if the other side could be caught somehow with the last clear chance to avoid Armageddon, so the long postwar crisis might settle on their favored equilibrium.  To counter this, both sides, again, had incentive to introduce the possibility of an irrational move—that if the crisis got too hot, things might slip out of control.  Actual play of the mutual deterrence game, then, went off equilibrium.  From the descent of the Iron Curtain to the dissolution of the Soviet Union itself, both governments refrained from humiliating the other side or going too far by demanding unconditional surrender, even as they “continued to play” and promise their populations they would eventually bury their ideological rival.

More than two decades after the Cold War, the nuclear arsenals of Russia and the United States remain sufficiently potent to support the scorpion analogy.  This will remain true even if both sides, as promised, implement the New START arms control agreement to reduce their strategic inventories to 1500 warheads each.  What is different, now, is the emergence of a sort of patchwork space within which nuclear armed rivals can play politics without engaging the ultimate threat.  The overarching Chicken game is still with us, but it lurks far in the background.  The action we observe resembles not so much competition in risk taking to discover who will belly up to world catastrophe.  Rather, the different sides, now, seem to be hopping about, searching for a patch on the geopolitical terrain, the right domain or the right means, where a stable correspondence might be restored between the balance of power and the balance of influence in Europe.

To this point, the Ukraine Crisis seems to be following a script more akin to Condorcet’s paradox than the old Chicken game.  In Condorcet’s scenario there was always some combination of forces available to thwart any apparent winner.  In Ukraine, at least during the early moves of spring 2014, during the forum-shopping for somewhere to resolve the competition among outside powers, there always seemed to be one more wrinkle to undermine previous gains for one side, pushing Ukraine first West, then East, then West, again.  Just as Schelling pointed out the element of irrationality complicating the Chicken analogy, there is likely to be one shaping the Great Powers’ version of Rock-Paper-Scissors, specifically, transaction costs.  Each move in isolation does not cost very much compared to the stakes of the crisis, but as time passes and the number of hops and shifts across domains mounts, these costs start to register, domestically as well as internationally, and make it more difficult to continue spinning on Condorcet’s cycle with no end in sight.

While waxing and waning of political influence in a strategic location like Ukraine may be gauged similarly by various players in contemporary power politics, the local balance of power has become a slippery concept, especially when mutual assured destruction, that is, the Schelling version of deterrence, has been, for the moment and by universal agreement, taken off the table.  Under the old Chicken game, different means were fungible according to a currency of risk—how these different means affected the one probability for general nuclear war.  Presently, in an era of cross-domain deterrence, the differences between ways and means, and their lack of convertibility to risk of a single cataclysm, are crucial to the outcome.  The object of cross-domain deterrence is to play through without entering classical deterrence, to keep finding new squares on the political chessboard with a home-court advantage, faster and cheaper than the other side can do the same.  The political and transactional costs of finding suitable, unlike responses to the rival’s next move mount until both players see value in quitting the game, which they are likely to do when the level of political influence in a contested theater roughly matches the local balance of power as revealed by cross-domain competition.

At the end of 2013, freely-elected pro-Russian president Viktor Yanukovych pulled Ukraine (GDP-2012 of $176 billion) out of a trade liberalization agreement with the European Union and instead accepted $15 billion in debt purchase and gas price reductions from Russia.  Protests, which began after Yanukovych’s rejection of the EU accord, ramped up in intensity.  Civilians stormed regional government offices in Western Ukraine, and protester deaths, injuries and destruction mounted in Kiev’s Independence Square (the Maidan).  Once President Yanukovych was forced to flee office in February 2014, Russia responded with open political and surreptitious military intervention in Ukraine.  To date, Russia annexed the Crimean Peninsula, home of its Black Sea fleet, after a shotgun referendum, and has offered diplomatic support along with an unknown amount of military assistance to heavily armed separatists in two eastern provinces, Donetsk and Luhansk.

Why has Russia not done more to split or neutralize Ukraine, especially earlier this year when its proxies appeared to have the military upper-hand in the eastern provinces?  The Ukraine crisis as it is playing out may be the latest example of successful cross-domain deterrence.


The sequence of thrusts and parries during the 2014 Ukraine Crisis maintained a furious clip for months after President Yanukovych canceled his trade agreement with the EU.  Remarkably, this pace, unlike the July Crisis of 1914, did not result in rapid escalation to general war.  Rather, more than seven months after initiation, this militarized dispute seems to be stabilizing rather than exploding.  Without the concepts of cross-domain deterrence (CDD), the reason for crisis dampening as opposed to explosive instability is puzzling.  After all, the frenetic activity, as in July 1914, took place within a context of great power rivalry.

The American narrative after the Cold War holds that victory for the West signaled at once the end of a terribly entrenched cycle of conflict and the dawn of a new historical epoch in which proud peoples of Europe, largely thanks to American intervention and protection, could prosper on a continent whole and free.  Russians, unsurprisingly, saw the dissolution of the USSR in mixed terms, the end of an oppressive regime, yes, but also the beginning of new vulnerabilities and exploitation by the West.  American behavior through NATO only confirmed these fears.  In stark geopolitical terms, the Western Alliance within a decade added twelve new nations in the strategic buffer zones of the Baltics, Central and Eastern Europe, and the Balkans.  In addition to enlarging its membership, NATO expanded its mission to include “out-of-area” military interventions in Serbia, Afghanistan, and Libya.

When President Yanukovch spurned the EU deal and accepted Russian aid instead in late-2013, Russian elites might have felt they had dodged a bullet.  Closer economic ties to the European Union, given the tenor of discussions and established patterns of Western behavior, could plausibly be the first step to EU and eventually NATO membership.  This eventuality would have meant yet another serious geopolitical defeat for Russia.  It would have left troubled and authoritarian Belarus as the only reliable insulation from NATO’s collective defense and crisis management alliance along the Russian frontier from the Baltic to the Black Sea.  With Finland already an EU member and Georgia chomping at the bit to enter NATO, energy interdependence notwithstanding, Russia would face the political and economic power of a united Europe, whole and in alliance with the United States, on a range of international questions of vital importance to all factions in Russia, not just President Putin’s political base.

Soon after the pro-Western Maidan protesters forced President Yanukovych to flee for Russia, well-trained, uniformed men without insignia, but using apparent equipment from Russia, set up military checkpoints.  Ostensibly, these deployments were in order to protect Russian speakers, which, conveniently for purposes of democratic legitimation, comprise the majority in Crimea.  Within two weeks, Ukrainian forces on the peninsula were locked down, leading to their eventual evacuation from Crimean bases.  Once service members loyal to the interim government in Kiev were neutralized, Crimea held a referendum on independence from Ukraine, followed by a vote to join the Russian Federation.  By March 18, President Putin of Russia requested and received a near-unanimous vote from the Russian Parliament to accept the Crimea.

Western diplomats framed these events as the first change in the borders of Europe through military operations since World War II, but Putin argued in several widely publicized speeches how annexation of Crimea followed democratic principles espoused by the Western powers during the enlargement of NATO and during the historic drive toward independence from Serbia for Kosovo.  Yanukovych, after all, had been elected president by all of Ukraine with strong support in the Crimea.  Citizens of Crimea had had no say in the euro-protests, which led to forceful occupation of government buildings across western Ukraine, violence at the Maidan, and overthrow of Ukraine’s constitutional government.

Within weeks of the annexation of Ukrainian territory, during the spring of 2014, the locus of action shifted to Donestk and Luhansk in the east.  Well-armed men, again without insignia but operating more as a grassroots militia than the crack units in Crimea had, began setting up checkpoints and occupying regional government buildings.  At first, the barely organized regime in Kiev seemed unable to respond with either police or Ukrainian army forces.  The interim Kiev government still suffered from self-inflicted wounds, having railroaded through laws during its first days in power against the use of Russian language for official business and pouring fuel on pro-Russian inhabitants’ desire to escape Kiev’s control.  Governments in Western Europe and the United States attempted to support Interim Prime Minister Arseniy Yatsenyuk and the shaky administration in Kiev.  Some $27 billion in Western aid, scheduled over several years, was cobbled together in March to replace the now defunct Russian package; targeted sanctions hit officials of the old Yanukovych regime and Russian elites close to President Putin in order to disrupt their lucrative business dealings; and Kiev received a series of invitations and visits from high profile leaders—Secretary of State Kerry, CIA Director Brennan, and Vice-President Biden from the United States alone.  Yet, though he received Prime Minister Yatsenyuk at the White House, President Obama stayed away from Kiev.  Though Putin was disinvited from the spring G8 summit, the reluctance of European Allies, particularly Germany, to expand sanctions and possibly disrupt energy flows from Russia was obvious.  In the run-up to the hastily called special election for choosing a new president of Ukraine, pro-Russian separatists backed by vocal diplomacy and under-the-table material aid from Putin seemed to have the upper hand.

Yet, after the successful campaign and election of Ukrainian billionaire Petro Poroshenko on May 25, momentum of the crisis over Ukraine shifted back against Russia, really for the first time since Maidan and the fall of Yanukovych.  The search began in earnest for a new equilibrium between East and West, both within the polarized Ukrainian state and across the broader canvas of European geopolitics.

In late May and June, the Ukrainian military responded to checkpoints and building occupations of separatists in the east.  Though pro-Russian irregular forces were well armed, capable, for example, of downing Ukrainian Army helicopters, there were clear limits to how long separatists could endure a conventional onslaught on their fixed positions without overt logistical support from Russia.  Though U.S. intelligence showed symbolic amounts of Russian equipment crossing the border, overarching movements sent the opposite signal—nearly 100,000 Russian troops first assembled on the Ukrainian frontier then went back to their bases before Russia decided to return with a much smaller force of several thousand in position for intervention, again demonstrating limits on what Russia was prepared to do militarily.

On the diplomatic front, the West shored up its commitment to NATO allies in the east, especially the Baltics and Poland, where movement of several Allied aircraft and about 800 U.S. personnel into the region coincided with President Obama’s state visit.  At the same time, lethal aid did not accompany intelligence support or the economic lifeline to Kiev:  President Obama publicly and repeatedly swept U.S. military action in Ukraine to neutralize Russian separatists off the table.  Instead, the Russians were said to risk even deeper sanctions if they overtly intervened to hive off eastern provinces from Kiev.  Meanwhile, President Putin negotiated a new natural gas supply agreement with China while jacking up prices against Ukraine, showing that world reaction to annexation of Crimea had not left Russia politically isolated.  Nevertheless, when asked precisely what Western deterrence measures affected, Germany’s defense minister in a June interview listed some key developments.

Western sanctions against pro-Putin oligarchs in Russia and Ukraine had not brought down the Russian economy directly but were associated with a more diffuse change in the investment climate such that foreign and Russian capital began to flee the country, tens of billions of dollars during the first quarter of 2014.  The longer Russian intransigence on the Ukraine crisis lasted, the greater the chance capital movement and associated difficulties in obtaining international financial credit could damage Russian economic growth.  The German defense minister also pointed to a shift in President Putin’s attitude toward the new government in Kiev.  Just before the Ukrainian special elections at the end of May, Putin agreed to recognize and work with the new president; this certainly undercut Yanukovych’s earlier claim, from exile in Russia, that he remained the legitimate president of Ukraine.  As of this writing, President Putin has urged inclusive talks on the future of Ukraine with President Poroshenko and encouraged pro-Russian separatists to “match” Poroshenko’s unilateral cease-fire in order to create space for negotiations.  While a NATO membership action plan (MAP) may be further off for Ukraine than it was immediately after Yanukovych’s ouster, the conciliatory moves toward equilibrium have taken place in the context of a new European offer to the Poroshenko government for some form of “EU association” with Ukraine.


Given the physical transfer of the strategically significant Crimean Peninsula from Ukraine to Russia under force of arms, this crisis is dangerous.  Yet, the rhythm of violence, the motion of forces, and the tone of rhetoric have settled remarkably from what they were in March 2014 as global attention shifted to Donetsk and Luhansk or even in February when Yanukovych abandoned the Ukrainian presidency.  The chances for escalation to a shooting war involving great powers, though necessarily subjective and likely low to begin with, have noticeably receded.  This is no mean accomplishment, a small decline in probability, admittedly, but for an event that would bring catastrophic costs to Europe, tragically undoing seventy years of peaceful development.  The Ukraine crisis, unfolding in the cradle of power politics on the hundredth anniversary of modern Europe’s Great War, thus indicates that cross-domain deterrence can succeed, indeed, may have a better chance of succeeding in a globalized and networked world.  Cross-domain deterrence appears to be working for three reasons.

First, responding to the military threat against Ukraine in the economic domain, with business sanctions and exclusion from the G8—traditionally a summit for financial matters—bought time for the status quo defenders in this crisis.  The economic moves did not hurt Russia immediately and may have even benefited President Putin with his domestic constituency in the short term, but they set in motion long-term costs such as capital flight.  Putin had days to assemble his intimidation forces on Ukraine’s northeastern border, but as days turned to weeks, the apparent costs of actually invading Ukraine mounted faster than the forces.  Time also allowed the new regime in Kiev to consolidate a proper constitutional government and execute a same-domain, classic denial response against pro-Russian separatists.

Second, cross-domain deterrence compared to classical deterrence as a competition in risk taking favors the deterring power.  The technology of globalization and networked communication makes it easier for the defender—in the classic formulation of a challenger/defender/target extended deterrence match-up—to find domains where he can exploit asymmetric vulnerabilities.  In classic, single-domain deterrence, when the challenger and defender are playing Chicken, the actor with higher tolerance for risk enjoys an advantage.  Linking domains can compensate against this leverage if new arenas provide an opportunity for a risk-averse player to impose high costs on, say, his Russian challenger, without suffering injury to himself.  In the metaphor of Gartzke and Lindsay, the defender changes the game on the challenger from Chicken to Rock-Paper-Scissors.

During the early stages of the crisis, several prominent realists pointed out that Putin was winning because the United States and Western Europe had no stomach for a larger fight over Ukraine.  This is still true, today, but crisis momentum has shifted anyway, toward a more favorable outcome for the West in part because, in a globalized economy with networked politics, relatively inexpensive, tailored sanctions led to capital flight that, regardless of President Putin’s risk propensity, Russia could not afford over the long haul.  It bears mentioning that, consistent with the Rock-Paper-Scissors metaphor, Russia succeeded concurrently in this crisis as a deterring power.  Faced with a political-economic challenge from the West, which toppled the amenable Yanukovich and threatened to capture Ukraine, plus Crimea, in NATO’s membership rolls, Putin executed an innovative, cross-domain blocking response.  He manipulated irregular forces, civilian protest, and constitutional politics to permanently secure the Crimean bases for Russia and yank Ukraine from NATO’s orbit.

Finally, cross-domain deterrence may be succeeding because globalization and networked politics in the past half-century have wrought fundamental structural change to world politics, not only in issue areas such as environmental protection and international finance, but in the hard core of national security.  In traditional security studies and classical deterrence, both scholars and practitioners identified important reasons for a status-quo power to contemplate a hard-slog use of force far on the periphery.  This made sense if nation-states’ defenses were akin to those of an amplifier.  Under this resonance condition, crises were such that they triggered reserves of energy in each actor in a reinforcing way, so the system became unstable:  parties locked themselves—like-move to like-move—in an escalation spiral as each tried to “deter” the other by winning the competition in risk taking.

After the revolution of globalization and political networks, militarized crises may no longer infuse energy into the system like amplifiers.  Rather, a dampening mechanism may supply a metaphor for contemporary, individual strategic defenses.  Today’s leading states, in response to a crisis on the periphery, perhaps have some way to form spicules, which are special geysers that divert energy from the sun’s central sphere, allowing temperatures on the outer corona of defense-in-depth to get very hot while the strategic core stays relatively cool.  Under these conditions, when two “centers of gravity” come into conflict in the international system, rather than locking them into high-energy great power war, militarized crises pass—unlike-thrust to unlike-thrust, dissipating energy across several domains—so key parties, mindful of their core, coolly sidle at lower overall energy levels, toward a new strategic equilibrium.  If fundamental system structure has evolved so that cross-domain deterrence is organic to modern great powers’ strategic defenses, this implies CDD can transfer energy away from fatal chains of dominoes leading from the periphery to core strategic interests.  In classical deterrence cases, the “domino effect” bedeviled crisis interactions on the periphery, transforming them into extremely dangerous escalatory events.  Chains of escalation and indeed classical deterrence are worth avoiding in favor of a cross-domain alternative during competitive adjustments to the international balance of power.  The old, same-domain approach, after all, brought horrific consequences during Cold War crises and, certainly, during the infamous July Crisis, which rapidly engulfed then decimated Europe after 1914.


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Welcome to the “Cross-Domain Deterrence” Blog! The “Cross-Domain Deterrence” research group is a group of professors, research scientists, and graduate students from University of California at San Diego, University of California at Berkeley, Lawrence Livermore National Labs, and Los Alamos National Labs, and housed at the University of California Institute on Global Conflict and Cooperation. We study mechanisms of deterrence in a shifting technological landscape, and in particular, how asymmetric capabilities; political, economic, and military linkages; and a wide-spectrum of actors influence deterrence strategies.

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