Russian military authorities likely expected to achieve a breakthrough in the northern shoulder of Ukraine’s defenses in the Donbas by this point – and failed. The reason is that Ukrainian troops continue to exceed expectations on the ground and Russian troops underperform (from inadequate/poor tactical pre-war training). In practical terms, however, the UAF’s successful defense results from the elaborate defenses Kyiv had ordered in the years since 2014.

The defenses in the Donbas include concrete bunkers, mutually-reinforcing positions, interlocking fields of fire, anti-tank mines, and pre-sited artillery targets on likely Russian avenues of approach. These defensive works and schemes have inflicted significant harm to attacking Russian troops and have been primarily responsible for preventing any penetrations thus far. This successful defense, however, has not been cost-free.