Ukraine and Assault River Crossings

A special assessment of potential assault river crossings by the Russians in Ukraine, the strategic rationale for these crossings, and the key principles for planning these complex operations.

Source: AUSA

A large river that crosses the direction of the attack is always very inconvenient for the assailant: when he has crossed it, he is generally limited to one point of passage, and therefore, unless he remains close to the river, he becomes very much hampered in his movements…a river is a substantial factor, for it always weakens and dislocates the offensive. Carl von Clausewitz, On War, 532-3.

Assault river crossings have featured in military operations since antiquity. During the Persian invasion of Greece in 480BC, Xerxes constructed a pontoon bridge across the Hellespont. The Siege of Antioch during the First Crusade (1097–1098), and the Siege of Damascus during the Second Crusade (1148) both featured military river crossing operations. The more modern wars of the 20^th century have also seen many assault river crossings as part of land campaigns in Europe and elsewhere.

River crossing operations are an important element of combined arms maneuver that modern armies have retained in their arsenals because of their enduring relevance. The current situation in Ukraine highlights again while modern armies prepare for such operations. In at least two parts of the front line in Ukraine, there is potential for river crossings in the short term.

There have been recent reports about the Russian Army planning to conduct an operation to cross the Dnipro River, with the possible aim of advancing on Kherson. On 2 December, the Institute for the Study of War reported that a Russian milblogger had amplified claims that Russian forces will renew offensive operations in western Zaporizhia Oblast some time after December 5 and that the Russians might also attempt a crossing of the Dnipro River somewhere in Kherson Oblast.

A spokesman for Ukraine’s southern command has also informed media that “Russian troops are constantly conducting assaults in the Kherson direction…They have the goal of capturing a certain bridgehead, holding it, and bringing them there as much of our strength and means as possible.”

More recently, the Kyiv Independent reported that the Russians are gathering boats for a crossing operation in the south. This story was accompanied by another which reported that Russian troops were sabotaging the boats being assembled for such a crossing.

In some parts of eastern Ukraine, the Russians have advanced to the eastern banks of the Oskil River. Early in December, Russian forces managed to cross the Oskil River near the town of Novomlynsk. They were thrown back across the river by Ukrainian forces. Anyone mildly familiar with terrain analysis and military tactics would assess that this was a crazy place to cross. The far bank (for the Russians) was dominated by high ground, and any bridgehead would have been dominated by the Ukrainians defending on this high ground.

Just to the south, the Institute for the Study of War has reported that the Russians are also advancing on the Oskil River, using Vyshneve and Pershotravneve (west of Svatove) as bases of operations. This may offer a more suitable crossing point in the future.

Military river crossing operations are difficult to plan and even harder to execute successfully. The many and varied challenges of terrain, river currents and riverbank profiles, approaches to the crossing site, the need for deception and the availability of bridging and rafts are magnified by enemy action designed to interfere with or halt friendly river crossings.

Back in May 2022, the Russians attempted an opposed river crossing of the Severskyi Donets in eastern Ukraine. This Russian river crossing operation gained a lot of attention at the time because it resulted in the loss of at least a Russian battalion tactical group as well as critical engineer equipment. It has been studied from multiple different perspectives since, including the application of combined arms operations, the training of troops, military leadership and operational art.

In the months after their liberation of western Kherson in November 2022, Ukrainian ground forces executed periodic crossings of the Dnipro River to conduct raids, harass Russian forces and capture prisoners for intelligence. But in October 2023, Ukraine executed river crossings at three different locations in Kherson. They were able to gain a small foothold at each location. While the Ukrainians were able to inflict casualties against the Russians over the following months, they were unable to make significant advances beyond their bridgeheads. By mid 2024, Ukrainian forces had withdrawn.

Therefore, it is fair to assert that river crossing operations have proven difficult for both sides in this war. None of the river crossing operations have proved decisive (yet). But, even the threat of such an operation must be addressed by a defender.

Before proceeding it is important to note that river crossings are only undertaken if absolutely necessary. The resources needed - engineers, bridges, artillery - are closely husbanded by senior military commanders. And it is always better to capture a bridge than having to build one! Therefore, such operations normally only occur on an axis of advance that is a main effort (or about to become the main effort).

The aim of this article is to explore the conduct of river crossing operations, and the principles that guide their planning and execution. Additionally, I will explore how these complicated activities are synchronised and the different phases that they are comprised of. Finally, the possible objectives of any future Russian river crossings in Ukraine are explored.