On Aug. 10, 2024, President Volodymyr Zelenskyy formally acknowledged that Ukraine’s military had invaded Russia’s Kursk region, along Ukraine’s northeast border. The offensive, which began on Aug. 6, marks the first time that Ukrainian regular forces have entered Russian territory. While declining to provide precise numbers, Ukrainian officials claim the attack involves “thousands” and includes tanks and armored vehicles.
Ukraine is playing offense. This shift in the war’s dynamics relates to a core concept in security studies: the “offense-defense balance.” Security studies scholars define this in terms of the relative costs and benefits of attacking versus defending: To what extent does it cost more, in blood and treasure, to launch an offensive as opposed to thwarting an opponent’s attack?
This Good to Know article explains the offense-defense balance and how it helps us understand the dynamics of the Russia-Ukraine war.
What happened in Kursk?
After months of incremental losses, Ukraine’s offensive has delivered impressive initial gains. Since early summer, Russian forces have been engaged in a grinding counteroffensive in Ukraine’s southeastern region. Those operations slowed in recent weeks, but Russia continued to take territory in the contested Donetsk region of Ukraine. Russia’s strategy, most likely, was to strengthen its demands that Ukraine must give up parts of this region as a condition for negotiations.
But the August 2024 surprise offensive reportedly helped Ukraine gain control of 1,000 square kilometers (386 square miles) of Russian territory within a week, including a natural gas transit hub.
In response to the largest incursion on Russia since World War II, President Vladimir Putin called Ukraine’s military operation a “major provocation.” Putin threatened to take “anti-terrorism” measures, including increased surveillance and restrictions on mobility in the region under attack. The Kursk acting governor announced a state of emergency, and Russia evacuated more than 76,000 people from the Kursk region’s border areas. As fighting edges close to Kursk’s nuclear power plant – the largest in the region – the International Atomic Energy Agency urged both Russia and Ukraine to “exercise maximum restraint.”
Given the secrecy involved in ongoing operations, it is difficult to know where the fighting stands, or guess Ukraine’s ultimate objectives. The political science literature on offensive strategies gives some important clues into why the Ukrainian incursion was able to make gains in Russian territory. This research also sheds light on Kyiv’s decision to go on the offensive, whether the invasion is legal, and whether this tactic is likely to succeed in the long run.
The Russia-Ukraine war and the offense-defense balance
What is the offense-defense balance? The literature analyzes the offense-defense balance at both the strategic and tactical levels.
For example, at the strategic level, scholars look at how geography or shifts in technology might give countries an offensive advantage. Technological innovations, such as those that allow militaries to project forces quickly, can favor the offensive. Geographical barriers, such as mountains and oceans, tip the balance towards defense.
Scholars warn that when people believe, rightly or wrongly, that going on the offensive offers an advantage, war is more likely. That’s because countries might be more willing to strike first against their opponents as a means to ensure their security. The perception – if not reality – of technological offense dominance before World War I drove France, Germany, and Russia towards strategies that required swift offensives against their opponents. This perception effectively pushed all sides towards initiating a major power war.
At the tactical level, scholars are more interested in how factors such as troop density, technology, surprise, and skill might allow for a successful battlefield offensive. At the end of World War I, both the Allied and Central powers innovated their offensive approach, adopting “fire and maneuver” tactics that allowed them to circumvent entrenched positions. In contrast, when there is little room to maneuver on the battlefield, offenses can become practically impossible. Certainly this has been the case in the Russian-Ukrainian war, as the development of sophisticated defense capacity on both sides brought ground offensives to a halt.
So how did Ukraine pull off its move into Russian territory?
Although technology played a role, it was not likely the primary factor. U.S. aid increased in May, but Ukraine is largely relying on the same technology that it has used for the last two years – including foreign–donated tanks, which it began receiving in early 2023.
Instead, these three factors help explain Ukraine’s decision to go on the offensive and cross into Russian territory. First, Russia had left the border with Kursk thinly defended. When Ukraine attempted to recapture occupied territory last summer, it faced a heavily fortified Russian defense. In Kursk, there was no “defense in depth” – Russia relied on only a thin and unfortified set of defenses along this border. In its initial response to the current Ukrainian offensive, Russia has relied mostly on units formed from conscripted soldiers and irregular forces without battle experience. These Russian units are at a disadvantage against the battle-hardened soldiers fighting for Ukraine.
Second, Ukraine likely had little difficulty maneuvering around Russia’s defenses and avoiding the heavy fire that has stymied operations elsewhere. The presence of both tanks and armored vehicles on the battlefront suggest that Ukraine’s forces are moving quickly to evade forces and capture Russian territory.
Third, Ukraine secured the element of surprise. All evidence suggests that Russia failed to see the offensive coming. How Ukraine pulled this off remains unclear. Ukrainian troops must have evaded Russia’s significant spy network and electronic surveillance capacity. Reports suggest that Ukraine may have jammed Russian communications and hacked into highway cameras along the invasion route to hide the advance.
And there may be cognitive factors behind this “surprise” as well. Did Russia think Ukraine was capable of this type of offensive? When cognitive beliefs are deeply established, a country may find it difficult to believe that an opponent will behave differently than expected – even in the face of concrete evidence. A member of Russia’s parliament has charged that Moscow’s leadership failed to heed intelligence reports of Ukrainian armed forces preparing to attack the region at least 48 hours before the assault began..
But why did Ukraine go on the offensive?
Kyiv’s offensive is a risky move. It required diverting troops from Donetsk, weakening that front where Russian troops have been trying to make further gains. And by sending regular forces into Russia’s territory, Ukraine risks further escalation from Russia.
Ukrainian officials have been tight-lipped about their strategic aims. Thinning Russia’s lines might help Ukraine in the short term. But in the long term, Russia’s advantage in numbers means that it should be able to reinforce its defenses in Kursk while maintaining offensive operations in Donetsk. The short term may be enough: If Ukraine can hold on into winter, it can rely on the weather to slow the Russians down.
Invading Kursk may bring political advantages. Over two years into the war, both sides have fought to a stalemate. While each side launches offensive operations, these end up grinding down into a war of attrition, where militaries rely on slow, cumulative losses for victory. In the face of these losses, there is increased talk of negotiations. A Zelenskyy aide has suggested that the ultimate aim of the offensive is bargaining leverage. If Ukraine can hold Russian territory, this may increase Kyiv’s bargaining capacity to demand a return of Ukrainian territory.
The current offensive may also help Kyiv rally support both at home and abroad. Ukraine’s population has shown signs of war-weariness. Polls indicate an increased willingness to negotiate, even with the loss of territory. To its international audience, Ukraine’s offensive may signal that military aid works, and that the boost in U.S. military support that began in May was a worthy investment.
Is the offensive illegal?
Putin claims that Ukraine’s actions are aggressive, and an attack on Russia’s security. Calling Russia’s reinforcement efforts “anti-terror” operations is not accidental. This wording helps Putin frame the Ukrainian offensive as illegal, suggesting that it violates international law. Ukraine, according to Putin, seeks to “destabilize the situation in Russia’s border regions.” Putin also called out the effort to “indiscriminately attack civilians” and “threaten our nuclear power plants.”
Russia’s efforts to undercut Ukraine’s legitimacy are not surprising. But military offensives are legal – if conducted with the legitimate aim of self-defense. One key insight of security studies literature is that offensive actions don’t necessarily result from aggressive intentions. If a country can make the case that only offensive operations can protect its sovereignty, then those operations are legitimate.
In this case, Ukraine has a strong case to make that its invasion is one of self-defense. There is the obvious point that Ukraine would not be in this war if Russia had not invaded in February 2022. It is Russia, not Ukraine, that invaded and now occupies substantial foreign territory. Tactically, Kyiv is coupling its 2024 incursion into Russian territory with attacks on Russian airfields that Russian forces have been using to strike targets across Ukraine.
Tactical gains don’t translate easily into strategic success
There is no doubt that Ukraine’s incursion caught Russia off guard, and galvanized calls for support across much of the international community. But the security studies literature on offensives offers a sobering lesson. The research suggests it’s difficult to convert tactical offensive success into strategic long-term gains, for several reasons.
First, these offensives typically grind to a halt as the other side goes on the defensive. As Russia diverts troops and reinforces its defenses, Ukraine’s offensive is likely to become another site of attritional war. Without the troop numbers to maintain the offensive, Ukraine will likely have to pull back. In a similar scenario, Germany used tactical innovations towards the end of World War I to make a number of substantial gains against France and Britain. It was a tactical success, but a strategic defeat. Lacking the numbers to reinforce those gains, Germany soon found itself retreating against Allied counter offensives.
Second, it is one thing to invade, and quite another to occupy territory. Kursk is not empty land. While over 100,000 Russian civilians have fled, Ukraine reports it has taken control of 82 settlements in Russia’s Kursk region. On Aug. 13, a Ukrainian spokesman clarified that “Ukraine is not interested in taking the territory of the Kursk region.” This statement might quell civilian unrest in the Kursk region, the research suggests. At the same time, this puts pressure on Ukraine to act quickly to achieve its strategic aims.
In other words, we are back to Carl von Clausewitz, the renowned German strategist who reminded us that “war is a mere continuation of politics by other means.” For Ukraine, the key now is to find a way to connect the August 2024 tactical success to a political goal.
Related Good Authority posts:
- Cynthia Buckley, Ralph Clem, Jarod Fox, and Erik Herron, “The war in Ukraine is more devastating than you know.” From April 2018, reporting on the extensive damage to hospitals in the Donbas fighting since 2014.
- Daniel Posthumus and Kelebogile Zvobgo, “The ICJ ordered Russia to halt military operations in Ukraine. What comes next?” From March 2022, when judges at the International Court of Justice ruled that Russia must suspend its military operations in Ukraine.
- Louis-Alexandre Berg and Andrew Radin, “Ukraine updated its defense institutions — and is defying expectations.” From March 2022, assessing Ukraine’s surprising resilience to the Russian invasion that began in February.
- John O’Loughlin, Gerard Toal, and Gwendolyn Sasse, “Do people in Donbas want to be ‘liberated’ by Russia?” From April 2022, reporting on a January 2022 survey in the contested Donbas region.
- Caitlin Talmadge, “Why Russia’s mobilization may lower the risk of nuclear war — for now.” From September 2022, as Russia’s invasion of Ukraine failed to produce a quick victory.
Further reading:
- Stephen D. Biddle, Military Power: Explaining Victory and Defeat in Modern Battle (Princeton University Press, 2004).
- Carl von Clausewitz, On War, edited and translated by Michael Howard and Peter Paret (Princeton University Press, 1976).
- David M. Edelstein, Occupational Hazards: Success and Failure in Military Occupation (Cornell University Press, 2008).
- Charles L. Glaser and Chaim Kaufmann, “What is the Offense-Defense Balance and Can We Measure it?” International Security, Vol. 22, No. 4 (Spring 1998), pp. 44-82.
- Robert Jervis, “Cooperation Under the Security Dilemma,” World Politics Vol. 30, No. 2 (January 1978), pp. 167-214.
- Seth G. Jones, Riley McCabe, and Alexander Palmer, “Seizing the Initiative in Ukraine: Waging War in a Defense Dominant World,” Center for Strategic and International Studies, October 23, 2023.
- Jack S. Levy, “The Offensive/Defensive Balance of Military Technology: A Theoretical and Historical Analysis,” International Studies Quarterly, Vol. 28, No. 2 (June 1984), pp. 219-238.
- Jack Snyder, “Civil-Military Relations and the Cult of the Offensive, 1914 and 1984,” International Security, Vol. 9, No. 1 (Summer 1984), pp. 108-146.
- Stephen Van Evera, “Offense, Defense, and the Causes of War.” International Security, Vol. 22, No. 4 (Spring 1998), pp. 5-43.
- Keren Yarhi-Milo, Knowing the Adversary: Leaders, Intelligence, and Assessment of Intentions in International Relations (Princeton University Press, 2014).
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