Big Serge has a detailed article on Operation Barbarossa which is well-researched, insightful, and very long. Anyone interested in WWII history, and anyone who hopes to make any sense of what is happening in Ukraine, would do well to read the entire thing.

Soviet preparation for war had focused on material factors – the sheer size of tank, artillery, and aircraft inventories – while neglecting the professional aspects of command, communications, and coordination. Consequentially, despite adequate equipment and weaponry, the Red Army was, very simply, outmatched by the nimbler and more responsive Wehrmacht.

In the first place, the performance of the Red Army cannot be separated from the fact that Stalin had conducted a widespread purge of his own officer corps only a few years prior to the outbreak of war. This appalling churn in the command hierarchy had occurred at the same time that the Red Army was expanding; as a result, Soviet officers tended to be rapidly promoted and were for the most part in over their heads early in the war, fighting a highly trained, experienced, coolly competent German officer corps, which had by now successfully undertaken two large campaigns in France and Poland, along with a variety of other specialized operations from Norway to Greece. The basic factors of experience and training were thus hilariously disposed in Germany’s favor.

At the same time, the Red Army lacked a dedicated communications system and relied on civilian telephone and telegraph lines, many of which were quickly cut by the Germans. It was not uncommon during the early phases of the war for Soviet officers to have to inquire with local communist party officials (the party did have access to wireless communications) as to where the Germans were and how far they had advanced.

The Red Army fought bravely but was unprepared for war at Germany’s pace
These two factors – an overwhelmed officer corps and a broken communications system – had a particularly deadly synergy. Different levels of the command hierarchy were cut off from each other and blind, while at the unit level, commanders were simply unable or unwilling to take initiative. Furthermore, the… shall we say peculiarities of the Stalinist system left the officer corps with instincts that were oriented towards political survival, rather than military exigency, and this meant not making drastic unilateral decisions.

This was an absolutely central aspect of war making that Stalin and the communists simply did not grasp; they had focused on churning out tanks, guns, and shells, while neglecting the command and control functions of the army. The Germans, quite simply, were prepared to fight war at a different pace than the Soviets: German commanders were more experienced, more decisive, more precise, more willing to act independently, and more level headed. The Red Army consequentially resembled an enormous, muscle bound fighter, but with a diseased nervous system and bad eyesight.

These vulnerabilities made the Red Army particularly susceptible to the Wehrmacht’s approach to warfighting, which brought overwhelming firepower and violence at the point of attack to allow rapid penetration and movement, creating an encircled pocket, or what the Germans called a kessel, for cauldron – which could then be liquidated. By fighting multiple kesselschlachts, or encirclement battles, the Wehrmacht planned to annihilate the Red Army and destroy the Soviet Union’s capacity to resist by the autumn of 1941. The objective was very clear: destroy Soviet fighting power. Annihilating the Red Army took absolute priority over capturing any specific geographic markers. Hitler himself had remarked that even Moscow was “of no great importance.” Rather, the objective of Barbarossa was to destroy Soviet manpower: “The mass of the army”, read the Barbarossa directive, “is to be destroyed in bold operations involving deep penetrations by armored spearheads, and the withdrawal of elements capable of combat into the extensive Russian land spaces is to be prevented.”

This last portion is the key to the concept of Barbarossa, but we shall return to this later.

The first shots fired in the cataclysmic Nazi-Soviet war came in the form of an aerial bombardment by the Luftwaffe, which attacked over 60 frontline Soviet air bases early on June 22. The Red Air Force lost over 1200 aircraft on the first morning of the war, ensuring German control of the air all along the line of contact. On June 24, literally two days into the war, Soviet western front headquarters informed Moscow that “Enemy aviation has complete air dominance.” The wholesale destruction of the Red Air Force’s frontline units was one of the most remarkable events in the history of warfare, yet it occurred so quickly that it receives scant mention in much of the war’s historiography; it is as if the Soviet air force simply vanished into thin air. Meanwhile, German advance teams managed to cut many civilian telephone and telegraph lines, throwing the Red Army’s command and control system into disarray and forcing the NKVD (which operated a wireless radio communication system) to act as middlemen to relay orders to the army. With the Red Army severely disoriented and bereft of air support, on came the fearsome German mechanized package.

The Soviet response was woefully inadequate. 1941 would be a year of terrible mistakes, but above all, what high level Soviet leadership – including and especially Stalin – did not understand was just how much could be won or loss in the opening moments of the war. By neglecting to put the Red Army on full combat alert, the regime allowed the Wehrmacht to achieve tactical, but not strategic surprise. Years later, one Soviet Marshal, Andrei Grechko, would make the tongue in cheek remark that the government and senior commanders were fully prepared for the outbreak of war, and the only people surprised by the German attack were the Red Army soldiers on the front line. What Stalin’s team did not comprehend was that tactical surprise, mixed with Germany’s particularly aggressive and mobile approach to war and the Soviet Union’s sclerotic command system, could produce a total catastrophe.

It is interesting to note that Big Serge tends to support Suvorov’s Icebreaker hypothesis, which is that Stalin was preparing to invade Central and Western Europe, but was taken by surprise by the timing and effectiveness of the German offensive. And indeed, the most convincing aspect of the hypothesis is the extreme forward placement of the 60 Soviet air bases, which led to the incredible destruction of the Soviet air forces.

it occurred so quickly that it receives scant mention in much of the war’s historiography

I would argue that it receives scant mention because it destroys the narrative that the German attack on the Soviet Union was unprovoked and took place solely as a consequence of Hitler’s vast imperial ambitions.