January 13, 2022
The Issue
If peace talks fail, the Russian military has several options to advance into Ukraine through northern, central, and southern invasion routes. But a Russian attempt to seize and hold territory will not necessarily be easy and will likely be impacted by challenges from weather, urban combat, command and control, logistics, and the morale of Russian troops and the Ukrainian population. The United States and its European allies and partners should be prepared for an invasion by taking immediate economic, diplomatic, military, intelligence, and humanitarian steps to aid Ukraine and its population and shore up defenses along the North Atlantic Treaty Organization’s (NATO) eastern flank.
Introduction
Russian president Vladimir Putin continues to threaten an invasion of Ukraine with a major military buildup near the Russian-Ukrainian border and aggressive language. Russia has deployed offensive weapons and systems within striking distance of Ukraine, including main battle tanks, self-propelled howitzers, infantry fighting vehicles, multiple launch rocket systems, Iskander short-range ballistic missile systems, and towed artillery, as highlighted in Figures 1a and 1b. Putin has complemented this buildup with blunt language that Ukraine is historically part of Russia and that Kiev needs to return to the Russian fold.1 Russia’s threat is particularly alarming for at least two reasons. First, Russia could move its pre-positioned forces into Ukraine quickly. If fully committed, the Russian military is significantly stronger and more capable than Ukraine’s military, and the United States and other NATO countries have made it clear they will not deploy their forces to Ukraine to repel a Russian invasion. Even if diplomats reach an agreement, Putin has shown a willingness to dial up—and down—the war in Ukraine and threaten to expand the war, making the Russian threat persistent. Second, an invasion would mark a significant change in international politics, creating a new “Iron Curtain” that begins along Russia’s borders with Finland and the Baltic states and moves south through Eastern Europe, the Middle East, Central and South Asia, and finally to East Asia along China’s southern flank.
Consequently, it is important to understand how Russia could invade Ukraine, how specific political objectives may influence an invasion plan, the challenges an invasion may face, and what options the United States and its European partners have to respond. To help understand these dynamics, this brief asks several questions. What are Russian president Vladimir Putin’s objectives? What military options does Russia have, and what might an invasion look like? How should the United States and its allies and partners respond?
The brief makes two main arguments. First, if Russia decides to invade Ukraine to reassert Russian control and influence, there are at least three possible axes of advance to seize Ukrainian territory: a northern thrust, possibly attempting to outflank Ukrainian defenses around Kiev by approaching through Belarus; a central thrust advancing due west into Ukraine; and a southern thrust advancing across the Perekop isthmus. Second, if the United States and its European partners fail to deter a Russian invasion, they should support Ukrainian resistance through a combination of diplomatic, military, intelligence, and other means. The United States and its European partners cannot allow Russia to annex Ukraine. The West’s appeasement of Moscow when it annexed Crimea in 2014 and then orchestrated an insurgency in Eastern Ukraine only emboldened Russian leaders. In addition, Russian annexation of some or all of Ukraine would increase Russian manpower, industrial capacity, and natural resources to a level that could make it a global threat. The United States and Europe cannot make this mistake again.
The rest of this brief is divided into three main sections. First, it examines Russian political objectives. Second, the brief analyzes Russian military options. Third, it explores options available to the United States and its allies and partners.
Figure 1a: Russian Military Buildup near Yelnya, Russia
Figure 1b: Close-Up of Russian Military Buildup near Yelnya, Russia
Russian Political Objectives
The Kremlin wants what it says: an end to NATO expansion, a rollback of previous expansion, a removal of American nuclear weapons from Europe, and a Russian sphere of influence. However, Putin may accept less. The Kremlin’s primary goal is a guarantee that Belarus, Ukraine, and Georgia will never belong to a military or economic bloc other than the ones Moscow controls and that Russia will be the ultimate arbitrator of the foreign and security policy of all three states. In essence, this conflict is about whether 30 years after the demise of the Soviet Union, its former ethnic republics can live as independent, sovereign states or if they still must acknowledge Moscow as their de facto sovereign.
Ostensibly, the demand for an exclusive sphere of influence in Eastern Europe and the south Caucasus is to meet Russian security interests. The Kremlin has portrayed NATO expansion to the east as the original sin of post-Soviet international relations with the West that now must be rectified. Facts, alternate interpretations, and the security concerns of equally sovereign nations notwithstanding, Moscow claims that without such guarantees, it will use military force to protect its security interests.
Russian Military Options
Based on these political objectives, the Kremlin has at least six possible military options:
1. Redeploy some of its ground forces away from the Ukrainian border—at least temporarily—if negotiations are successful but continue to aid pro-Russian rebels in Eastern Ukraine.
2. Send conventional Russian troops into the breakaway regions of Donetsk and Luhansk as unilateral “peacekeepers” and refuse to withdraw them until peace talks end successfully and Kiev agrees to implement the Minsk Accords.
3. Seize Ukrainian territory as far west as the Dnepr River to use as a bargaining chip or incorporate this new territory fully into the Russian Federation. This option is represented in Figure 2a.
4. Seize Ukrainian territory up to the Dnepr River and seize an additional belt of land (to include Odessa) that connects Russian territory with the breakaway Transdniestria Republic and separates Ukraine from any access to the Black Sea. The Kremlin would incorporate these new lands into Russia and ensure that the rump Ukrainian statelet remains economically unviable.
5. Seize only a belt of land between Russia and Transdniestria (including Mariupol, Kherson, and Odessa) to secure freshwater supplies for Crimea and block Ukraine’s access to the sea, while avoiding major combat over Kiev and Kharkiv. This option is represented in Figure 2b.
6. Seize all of Ukraine and, with Belarus, announce the formation of a new tripartite Slavic union of Great, Little, and White Russians (Russians, Ukrainians, and Belarusians). This option would involve operations represented in Figure 2a as “phase one,” with Figure 2c representing “phase two” of this option.
Of these six options, the first two are the least likely to incur significant international sanctions but have limited chance of achieving a breakthrough on either NATO issues or the Minsk Accords due to their coercive nature. All other options bring major international sanctions and economic hardship and would be counterproductive to the goal of weakening NATO or decoupling the United States from its commitments to European security.
Options three through six could achieve another goal—the destruction of an independent Ukraine—whose evolution toward a liberal democratic state has become a major source of contention among the Kremlin’s security elites. Option three would have Russia control a substantial amount of Ukrainian territory but still leave it as an economically viable state. Option four leaves only an agrarian rump Ukraine but precludes occupying its most nationalistic areas. Option five leaves more of Ukraine free but still cuts its access to the sea and incurs fewer occupation costs. Options four and five—seizing a belt of land from Tiraspol to Mariupol—are complicated by the fact that there is no east-west running natural feature, river, or mountain range that could serve as a natural line of demarcation for this occupied land. The new border along this territory would run across countless fields and forests and be difficult to defend. Option six means occupying the entire country and dealing with the assimilation of a population of 41 million that may resist occupation actively and passively for years. It would require an occupation force of considerable size to control the population and man the new borders with NATO countries. Ukrainians in any occupied territory can expect forced Russification that the nation experienced under such rulers as Catherine the Great, Alexander II, Stalin, and Brezhnev.
Possible Invasion Routes
Ideological preparation of Russian society for a conflict with Ukraine has been ongoing since at least 2014, with Kremlin propaganda portraying Ukraine as a proto-fascist, neo-Nazi state. In July 2021, a public letter by President Putin asserted that Russians and Ukrainians are the same people and castigated Ukraine’s authorities for justifying independence by denying its past.2 The Russian military made President Putin’s article compulsory reading for its soldiers.3 This was followed in October by a letter in the newspaper Kommersant by Russian Security Council vice-president Dmitry Medvedev, which used antisemitic tones to delegitimize the current Ukrainian leadership as extremist, corrupt, and foreign controlled.4
With an ideological basis for action in place, the next step is to create a casus belli—justification for war—consistent with the Kremlin-manufactured image of Ukraine. Pretexts for an attack could range from a straightforward breakdown of security talks to a stage-managed incident similar to the provocations at Mukden, Gleiwitz, and Mainila that provided justification for Japan’s invasion of Manchuria, Germany’s invasion of Poland, and the Soviet Union’s attack on Finland, respectively. This is why the bizarre claim of Defense Minister Sergey Shoigu posted on the Kremlin’s official website of American mercenaries preparing a “provocation” with chemical weapons in Ukraine is ominous and might foreshadow just the type of “incident” the Kremlin would prepare.5
Once the
