The preparations were carried out for years on both sides, as Ukraine and Russia exchanged fires on the Eastern front of Donbas and Luhansk in 2013. Over the past eight years, Russian special forces assisted the Ukrainian separatists in these regions but did not move forward or out of areas occupied in 2014. On the other side, Ukraine increased its military force, investing in the local manufacturing of new equipment and modernization of equipment initially produced in the Soviet era.

The Ukraine military received substantial numbers of new equipment developed and produced by the local defense industries and received new equipment and training provided by Western countries, primarily the USA, UK, and other NATO members. In late 2021 the Russians began concentrating large forces in Belarus and the areas of Western Russia bordering Ukraine. These forces included 10 Russian armies gathered from the Eastern, Central, Western, and Southern military districts, all these forces arrived in Western Russia to take part in extensive military exercises with Belarus. After completing those exercises, about 120 Battalion Tactical Groups (BTGs) were deployed along the Ukraine borders, ready to move south and west into Ukraine if ordered. The units from the Southern District have joined two armies of Russian-backed Ukrainian separatists from the Donbas.

Russian Battalion Tactical Group

The BTG is the primary combined-arms fighting unit of the Russian Army. Since 2012 about 170 BTGs have been established by grouping available assets and training troops to fight as independent combined arms teams. The BTG is designed as an agile, maneuverable formation that possesses high levels of organic firepower, enabling it to operate for a limited scope without fire support from higher echelons. The BTG is a powerful, armored-vehicle heavy formation, mobilizing 75 tanks, artillery (howitzers and rockets), mobile air defense, and combat engineering assets. BTGs were envisaged as multi-theater operators, with the ability to shift from rapid assault to long-range attacks or support other units. The BTG formation has about 3,000 troops, but only 200 are infantrymen, a relatively small number required to defend the battalion in complex terrain and on marching orders. While the BTG’s combat element is designed to operate across the landscape, they are dependent on the extensive logistical tail of the service and support that binds those combat elements to roads. In the Ukraine north sector, those vulnerabilities were fully exploited by the defending troops during the first phase of the war.

At the time of the Russian buildup, tension increased as Moscow demanded Kyiv refrain from its bid to join NATO and the EU. While NATO did not invite Ukraine to join, fearing they would have to confront the Russian Army under the alliance’ Article 5 commitment, almost all NATO member nations rushed to help Ukraine defend itself. They sent large numbers of anti-aircraft and anti-tank weapons that could be rapidly deployed to the front lines and be used without a complex logistical footprint.

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