How Russia Decides When to Invade

The world is looking fearfully at the Russian-Ukrainian border and for good reason. Russia has amassed some 120,000 troops on the border, and fighting along the line of contact between Moscow-backed separatists and Ukraine’s security forces has intensified in recent days. Signs at the top are no better. The Russian Ministry of Foreign Affairs released a draft proposal on Dec. 17 detailing security guarantees between Russia and the United States that explicitly draws a red line on NATO’s expansion eastward to Ukraine and other former Soviet states, and Russian President Vladimir Putin issued an ominous warning on Dec. 21 of a “military-technical” response to what he deemed as “aggressive” measures by the West.

U.S. and other Western officials have already deemed many of Russia’s proposals “unacceptable,” though the urgency of the situation has spurred plans for security talks between the United States and Russia in January. While many have tried to read the tea leaves and psychoanalyze Russian President Vladimir Putin as to whether or not he will actually make the decision to invade Ukraine, there is a broader structural framework for understanding and anticipating Russian military interventions in the post-Soviet space that can perhaps be a more useful guide. Despite all the hard words from Moscow, Russia’s record shows that an invasion is unlikely.

What specific objectives would Putin have in launching an invasion? The answer to this question must be rooted in Russia’s geopolitical imperatives, which frame all manners of Moscow’s decision-making. Russia’s primary imperatives are domestic political consolidation on the homefront, protecting itself from external threats (whether that be from neighbors or global powers), and expanding its influence both regionally—especially in the countries of the former Soviet Union—and beyond to the extent possible.

The expansion of NATO to the former Soviet bloc thus violates a key imperative for Russia, which leaves Moscow feeling fundamentally insecure both from neighboring countries that join the bloc and the external powers—primarily the United States—that support them. While Russia was too weak to stop NATO expansion into Central Europe and the Baltic states in the 1990s and early 2000s, Moscow was willing to go to war in Georgia in 2008 and subsequently in Ukraine in 2014 to stop this from happening. But even this decision was not taken lightly or indiscriminately by the Kremlin, which brings us back to the framework on Russian military interventions.

In its decision-making process on whether to intervene militarily in the former Soviet sphere, Russia’s calculus uses a strategic framework that rests primarily on five variables: 1) a trigger; 2) local support; 3) anticipated military reaction; 4) technical feasibility; and 5) relatively low anticipated political and economic costs, especially when it comes to nonmilitary responses to invasion such as sanctions or diplomatic restrictions.

If any one of these conditions is insufficient or nonexistent, then Russia is unlikely to intervene militarily, even within the former Soviet space. If all these factors are present, there is a much higher likelihood for a Russian military intervention. And if Russia gambles wrong, it pays a very high cost.

Take Russia’s invasion of Georgia in 2008—each of the five variables was met. The trigger came in the form of Georgian shelling of South Ossetian villages. The local support for Russian intervention was strong but only in the regions of South Ossetia and Abkhazia, with Russia not sending its ground forces into Georgia proper, where local support was much weaker. Russia had direct access to Georgia via the Rokhi tunnel, and Georgia’s military forces were much weaker than those of Russia, making the intervention technically feasible. Georgia was not yet a NATO member state, and Moscow calculated that the West’s response would be relatively limited and the costs were thus manageable. Russia’s objective was to undermine Georgia’s pursuit of NATO accession, and the result was the 2008 Russia-Georgia War.

In the case of Russia’s invasion of eastern Ukraine in 2014, the five variables were met once again. The trigger was the Euromaidan Revolution, which ousted Ukraine’s pro-Russian president, Viktor Yanukovych. Local support for Russia’s intervention was strongest in Crimea and the Donbass region of eastern Ukraine, but it was very limited in the rest of the country. Logistically, Russia already had troops in Crimea and had direct access to Donetsk and Luhansk regions, but going farther into Ukraine would have entailed long supply lines and more actively hostile political territory. Like Georgia, Ukraine was not yet in NATO, and Moscow calculated that the bloc would not intervene in the event of military action. Russia’s objective was to undermine the pro-Western government of Ukraine and prevent NATO accession, and the result was the annexation of Crimea and the ongoing separatist conflict in eastern Ukraine that continues to this day.

There are other instances where Russia did not intervene militarily despite having a perceived justification. For example, Russia did not invade Estonia in 2007 following the Bronze Soldier incident, though it had the perceived justification in terms of protecting ethnic Russians. The reason: Estonia was already a NATO member, and the potential costs for a Russian military intervention were perceived as too high. Russia also did not intervene militarily in ethnic clashes between Kyrgyz and Uzbeks in southern Kyrgyzstan in 2010, despite being asked by the Kyrgyz government to do so. Such an intervention was not necessary for Russia to achieve any of its imperatives, and there was no NATO threat, so the costs outweighed the benefits.

Which takes us back to the original question at hand: Is Russia about to invade Ukraine—again? Firstly, what specific goal Russia would have in invading Ukraine now? There is no clear answer to this, other than further undermining the Ukrainian government, using revanchism to shore up domestic support, or sending a message to the West. Without a core trigger, an intervention seems unlikely. But such a decision could backfire and push Ukraine even closer into NATO, violating one of Russia’s core imperatives. And while each of the five variables was in place for a Russian invasion in 2014, many of these have shifted. For example, Ukraine now has much greater support from the West, and even though it is not a NATO member, the economic, political, and potentially military costs for Russia would be significantly higher. Furthermore, the local support within Ukraine for a Russian invasion would be much lower now than in 2014, with the exception of the existing strongholds in the Donbass and Crimea, where Russia already has troops and/or military personnel.

Thus, the application of this framework on military intervention suggests that a looming large-scale Russian invasion of Ukraine is unlikely. However, this does not preclude alternative, nonconventional military measures by Russia. These could entail various aspects of hybrid warfare, such as covert activity, political manipulation, cyberattacks, propaganda, and misinformation—including the signaling of a potential invasion that we are seeing now. There is also the possibility of Russian military buildups elsewhere, such as weapons deployments to Kaliningrad or in countries that are friendlier to Moscow, such as Belarus.

A Russian invasion of Ukraine is not impossible, as the conditions could certainly shift to lead to a different calculus for Moscow in the future. Furthermore, this framework is not a specific blueprint rooted in any particular policy documents but rather an empirically driven model based on observations of trends and Russian decision-making in the military sphere under Putin’s rule.

But a close reading shows that Russia’s use of military force in the Putin era—while often appearing aggressive and erratic—is actually rather conservative and risk-averse, with a strong cost-benefit analysis taken by the Kremlin in each particular case. Using such a framework, it is possible to not only understand Russia’s military interventions in Ukraine and elsewhere in the former Soviet space but also to anticipate them ahead of time.