Russian and Soviet doctrine
Deep operation, echelons, and the tank as a cheap operational tool.
Deep battle
Soviet operational art (Tukhachevsky, then postwar STAVKA manuals) treats the tank army as the tool that rips through a defense after artillery and aviation have broken a corridor. The unit of decision is the army and the front, not the platoon. Individual tanks are allowed to die if the rate of advance holds.
Design for the railroad
Soviet loading gauge and bridge class kept tanks near 40–48 t for decades. Autoloaders shrank the turret. The gun fired HE-Frag in bulk because the next target was an AT gun, not another tank. Snorkels, wide tracks, and diesel heat in winter are operational features. Export T-72s were downgraded because the real war was in Germany.
What 2022 changed
Drones, artillery, and mines have punished echeloned armor that outruns air defense and infantry. Russia still fields T-72B3, T-80BVM, and T-90M because those are the tanks that exist. T-14 remains a statement. The doctrine is being rewritten under fire: smaller packets, more ERA and cope cages, more concern for the top arc. The industrial instinct — build many, accept losses — has not vanished.