Russia’s War in Ukraine: Military and Intelligence Aspects

Introduction ..................................................................................................................................... 1

Prelude to Invasion: Military Buildup and Force Posture ......................................................... 1

Initial Invasion ................................................................................................................................. 4 March-May 2022 ............................................................................................................................. 7 May-September 2022 ...................................................................................................................... 9

Kherson Region Offensive ...................................................................................................... 12 Kharkiv Offensive ................................................................................................................... 13 Russia’s Claimed Annexation of Ukrainian Territories ........................................................... 14

October 2022-March 2023 ............................................................................................................ 15 April 2023-Fall 2023 ..................................................................................................................... 20

Ukraine’s Summer 2023 Counteroffensive ............................................................................. 23

Russia’s Defense Industrial Base ................................................................................................... 29 Outlook .......................................................................................................................................... 30

Issues for Congress ................................................................................................................. 32

Figures Figure 1. Ukraine ............................................................................................................................. 3 Figure 2. Donbas Region of Ukraine ............................................................................................... 9 Figure 3. Ukraine Airfields and Key Infrastructure ....................................................................... 16 Figure 4. Ukraine Territorial Control, Winter 2022-2023 ............................................................. 17 Figure 5. Russian Command and Control in Ukraine ................................................................... 23 Figure 6. Southern Ukraine Territorial Control ............................................................................. 25

Contacts Author Information ........................................................................................................................ 33

Introduction Russia’s renewed invasion of neighboring Ukraine in February 2022 marked the start of Europe’s deadliest armed conflict in decades and prompted intensive international efforts to respond to the war. Multiple Members of Congress have engaged with U.S. and international measures, including by supporting sanctions against Russia, providing assistance to Ukraine, and bolstering support to neighboring NATO countries. The immediate and long-term implications of the ongoing war are likely to be far-reaching, affecting numerous policy dimensions of concern to Congress.

This report addresses Russian and Ukrainian military and intelligence aspects of the war, which are of interest to many in Congress as Congress considers various legislative measures and conducts oversight of U.S. policy. It provides an overview of the conflict, including the run-up to the invasion, the various phases of the war to date, recent developments on the ground, and the conflict’s near-term outlook. The report includes brief discussions about potential Russian war expectations and military command and personnel challenges. For other CRS products related to Russia’s invasion of Ukraine, including U.S. policy dimensions, see CRS Report R47054, Russia’s War Against Ukraine: Related CRS Products .

Prelude to Invasion: Military Buildup and Force Posture In mid-October 2021, social media and news outlets began to report significant movement by Russian military forces, with limited Russian transparency, on or near the Ukrainian border and within Ukraine’s occupied Crimea region (which Russia claimed to annex in 2014). The buildup came after a sustained increase in Russia’s permanent force posture on the Ukrainian border. Since 2014, Russia has created two new Combined Arms Armies (CAAs), one in the Western Military District (20th CAA, headquartered in Voronezh) and one in the Southern Military District (8th CAA, headquartered in Rostov-on-Don and Novocherkassk) bordering Ukraine. Russia created these CAAs to oversee, coordinate, and manage command and control of units transported to the border. The 8th CAA also reportedly commands the separatist units in two Russia-controlled areas in eastern Ukraine (the so-called Donetsk and Luhansk People’s Republics, or DNR/LNR).

Throughout December 2021, Russia continued to build up its forces in the region. Prior to the February 2022 invasion, Russia had mobilized between 150,000 and 190,000 personnel and 120 Battalion Tactical Groups (BTGs) on its border with Ukraine,1 in Belarus, and in Ukraine’s occupied Crimea region, according to U.S. government estimates.2

1 Battalion Tactical Groups (BTGs) are ad hoc, task-specific formations designed to operate autonomously as combined arms formations. BTGs are built around infantry and armor units, with supporting air defense, artillery, and other units. BTGs comprise the higher readiness units of the Russian military and are staffed by professional (also known as contract) personnel. Each Russian regiment or brigade is intended to generate two BTGs. In August 2021, Russian Defense Minister Sergei Shoigu stated the Russian military had 168 BTGs. Lester W. Grau and Charles K. Bartles, The Russian Way of War: Force Structure, Tactics and Modernization of the Russian Ground Forces (Leavenworth, KS: Foreign Military Studies Office, 2016), pp. 34-40; Tass, “Russian Army Operates Around 170 Battalion Tactical Groups—Defense Chief,” August 20, 2021.

2 U.S. Mission to the Organization for Security and Cooperation in Europe, “U.S. Statement for the Vienna Document Joint PC-FSC Chapter III Meeting,” February 12, 2022; Department of Defense, “Senior Defense Official Holds a Background Briefing,” press release, March 3, 2022.

Prior to the February 2022 invasion, the Russian military was a tiered readiness force, with units varying in levels of staffing and readiness.3 Additionally, since 2012-2014, Russia has expanded its ground forces structure by creating new units without increasing the available personnel. However, as new units were created, the actual staffing level was reduced further due to insufficient personnel. Each Russian brigade or regiment is intended to field and deploy two Battalion Tactical Groups (BTGs) of 700-900 contract soldiers (a third would consist of conscripts), but it became clear that the BTGs varied in staffing levels. Some BTGs deployed with 400-600 contract personnel. The result was that the Russian military had a relatively limited core of deployable maneuver combat formations of contract personnel relative to the total size of the military.4

During this buildup, analysts documented the movement of Russian units from across Russia toward Ukraine.5 The 41st and 2nd CAAs moved from the Central Military District into Belarus and to Ukraine’s northeast border with Russia; the 1st Guards Tank Army and the 6th CAA moved from the Western Military District to Ukraine’s eastern border with Russia; the 49th and 58th CAAs moved from the Southern Military District to occupied Crimea and to Ukraine’s southeast border with Russia; and the 35th and 36th CAAs (and elements of the 29th and 5th CAAs) moved from the Eastern Military District to Belarus.6 In addition, Russia deployed elite units—such as Russian Airborne (VDV), Naval Infantry, and spetsnaz (elite light infantry units used for reconnaissance and direct action)—around Ukraine’s borders.7