Lessons of the Ukraine War Thus Far

The all-out Ukrainian war, waging now for seven months, has already provided several valuable lessons. Indeed, the fighting has tested various prewar ideas on military development that had been widely discussed among Ukrainian military experts before the war. As Russia continues to be an imminent military threat to Ukraine, it is critical to properly distill lessons learned from the first seven months of fighting that will certainly guide the future of the Ukrainian military.

To begin, the idea of a peacetime small contract army was quite popular in Ukraine before 2022. It was assumed that the decrease of active-duty troops in the armed forces during peacetime would augment the share of the national defense budget dedicated to maintenance and the purchase of new hardware (Ussi.org.ua, October 25, 2020).

Maintaining a small contract army during peacetime is considered a relic of a more peaceful post–Cold War period. In the 1990s and 2000s, it was assumed that a major task for the military would be stabilization and humanitarian operations in which swift reactions would be considered more important than the mass of troops involved.

Developments since the February 24 invasion have made clear that the peacetime strength of 215,000 troops in the Ukrainian Armed Forces was not enough to effectively cover all major operational directions. The shortage of fully manned formations was especially acute in southern Ukraine. Only makeshift popular mobilization compensated for the lack of manpower proportionate to the scale of theater for early military operations. Currently, Ukraine has a government-estimated 1 million men and women under arms that include the defense and security sectors (Forbe.ua, July 8). Meanwhile, the Russian Armed Forces are constantly feeling the strain of major manpower issues—a thinned front line and lack of reserves were key factors for Russia’s failure in the face of Ukraine’s offensive operation launched in the Balakliya-Kupyansk direction (Financial Times, September 13). The need to buttress front-line units with more troops shall be considered as the main driver of official mobilization declared by the Russian president on September 21.

Moving forward, any discussion of hypothetical peacetime strength shall proceed from the understanding that Ukraine needs an enlarged peacetime contract army numbering approximately 300,000 to 350,000 men under arms. Such a force will make it possible to accomplish all necessary tasks during any initial period of hostilities—effectively covering all major operational directions, gaining time for internal and external mobilization, exhausting the enemy’s offensive capabilities and minimizing its inroads into Ukrainian territories, thus laying conditions for an effective counteroffensive. In this context, it is telling that Poland decided to increase the strength of its armed forces from 143,000 to 300,000 in the next five years (Voice of America, April 21). Warsaw’s plan is telling as Poland has less lengthy common border with Russia and Belarus than Ukraine but at the same time has NATO security guarantees, which Ukraine lacks for now.

To this end, an increased number of regular contract troops demands an overhaul of the Ukrainian army’s command structure. One possible variant might be the creation of an intermediate level of command similar to the use of military districts during peacetime, which would assume control of different formations in separate operational directions.

Additionally, the idea of so-called “non-nuclear” deterrence by means of a small number of conventionally armed mid-range missiles was also widely discussed in Ukraine before Russia’s aggression. At the time, it was assumed that the threat of dozens of mid-range surface-to-surface missiles would be enough to deter hypothetical all-out Russian aggression, or at least bring it to a favorable conclusion quickly (Ussi.org.ua, October 17, 2019). Real-world developments call into question the ability to quickly cease hostilities on favorable terms with such a small number of missiles.

First, Russia has fired more than 3,800 missiles against Ukraine of all different types (President.gov.ua, September 15). These missiles are made up, in large part, by so-called “theater of operations” missiles—mid-range missiles that can strike targets thousands of kilometers away (e.g., Kalibr and X-101). But such a quantity of missiles, which is much more than the United States has launched in total in the past 40 years, did not allow Russian forces to change warfighting dynamics in a favorable way—by failing to paralyze railways logistics, interdict Western military supply flow to Ukraine or gain air superiority.

Furthermore, the Ukrainian experience has made clear that precision missiles of lesser range combined with accurate intelligence can make a world of difference on the battlefield. Primarily, this concerns the employment of Guided Multiple Launch Rocket System (GMLRS) projectiles guided by GPS with an 85-kilometer range. The US has provided Ukraine with at least 2,100 projectiles of this type, based on US Department of Defense statistics (Defense.gov, August 29). With these projectiles, Ukraine was able to both strengthen its defense targeting of Russian artillery warehouses deep in their rear and lay the preconditions for switching to the offensive in the Kherson and Kharkiv regions, targeting bridges, command-and-control nodes and logistics.

Basically, successful mass employment of GMLRS by Ukraine has proven the validity of the US Army’s AirLand Battle doctrine of the 1980s. Originally, this doctrine was designed as a response to the Soviet Union’s numerical conventional superiority threatening Western Europe. It was assumed that by precision conventional in-depth strikes the US and its allies would attrit the Soviet follow-on echelon before it would make a difference on the front line. With GMLRS, Ukrainian forces were able to negate Russia’s advantage.

Even so, this does not mean that Kyiv will cease to ask for short-range ballistic ATACMS (Defense News, August 31). Quite the opposite in fact, as Ukrainian Commander-in-Chief Valerii Zaluzhnyi recently made clear that Ukraine will continuously request ATACMS (Ukrinform, September 7). Indeed, based on the current positions, only with ATACMS can Ukrainian forces destroy all supply targets in Russia’s rear.

Ukraine has also learned a great deal regarding territorial defense. In 2021, reform of the territorial defense forces (TDFs) was quite popular. This was done through institutionalization of a separate command chain responsible directly to the commander in chief, with each region having its own brigade (Come Back Alive, May 16, 2021). It was assumed that, in rear areas, TDFs would relieve security and defense forces while combating the sabotage of local pro-Russian groups. In border areas, it was assumed implicitly that territorial defense brigades would complement security and defense forces while repelling Russian assaults.

As the Law on the Fundamentals of National Resistance entered into force only at the beginning of 2022, the Ukrainian Armed Forces had little time to implement all the provisions related to TDFs before February 24. As a result, deployment of TDFs was completed during the actual fighting.

Even the makeshift character of territorial defense’s major deployment made clear its advantages—especially in border regions. Territorial defense either complemented regular formations in creating lines of resistance along major urban areas (Kyiv, Chernihiv, Kharkiv and Mykolaiv), or used porous front lines to attack Russian unsecured lines of communications. In the end, TDFs enabled the addition of approximately 200,000 troops to regular formations quickly.

The high price paid by Ukraine for these lessons learned should not be disregarded. Now, after seven months of fighting, it is evident that enlarged peacetime contract armed forces, coupled with reinforced TDFs and augmented with battlefield precision reconnaissance-strike complexes, will ensure that any future Russian offensive will be met with forceful and effective resistance from the very beginning.