Recapture of the city by the Soviet 39th, 43rd and 10th Guards armies
The second Smolensk operation (code naming "Suvorov"; 7 August – 2 October 1943) was a Soviet strategic offensive operation conducted by the Red Army as part of the Summer-Autumn Campaign of 1943. Staged almost simultaneously with the Lower Dnieper Offensive (13 August – 22 September), the offensive lasted two months and was led by General Andrei Yeremenko, commanding the Kalinin Front, and Vasily Sokolovsky, commanding the Western Front. Its goal was to clear the German presence from the Smolensk and Bryansk regions. Smolensk had been under German occupation since the first Battle of Smolensk in 1941.
Despite an impressive German defense, the Red Army was able to stage several breakthroughs, liberating several major cities, including Smolensk and Roslavl. As a result of this operation, the Red Army was able to start planning for the liberation of Belarus. However, the overall advance was quite modest and slow in the face of heavy German resistance, and the operation was therefore accomplished in three stages: 7–20 August, 21 August – 6 September, and 7 September – 2 October.
Although playing a major military role in its own right, the Smolensk operation was also important for its effect on the Battle of the Dnieper. It has been estimated that as many as 55 German divisions were committed to counter the Smolensk operation – divisions which would have been critical to prevent Soviet troops from crossing the Dnieper in the south. In the course of the operation, the Red Army also definitively drove back German forces from the Smolensk land bridge, historically the most important approach for a western attack on Moscow.
Constituent operations.
The strategic operations included smaller operations:
Strategic context.
By the end of the Battle of Kursk in July 1943, Germany had lost all hope of regaining the initiative on the Eastern Front. Losses were considerable and the whole army was less effective than before, as many of its experienced soldiers were killed during the previous two years of fighting. This left the German army capable of only reacting to Soviet moves.
On the Soviet side, Joseph Stalin was determined to pursue the liberation of occupied territories from German control, a course of action that had its first major success at the end of 1942 with Operation Uranus, which led to the liberation of Stalingrad. The Battle of the Dnieper was to achieve the liberation of Ukraine and push the southern part of the front towards the west. In order to weaken the German defenses even further, however, the Smolensk operation was staged simultaneously, in a move that would also draw German reserves north, thereby weakening the German defense on the southern part of the front. Both operations were a part of the same strategic offensive plan, aiming to recover as much Soviet territory from German control as possible.
Thirty years later, Marshal Aleksandr Vasilevsky (Chief of the General Staff in 1943) wrote in his memoirs:
This plan was enormous both in regard of its daring and of forces committed to it, was executed through several operations: the Smolensk operation, ...the Donbass [Operation], the left-bank Ukraine operation...
Geography.
The territory on which the offensive was to be staged was a slightly hilly plain covered with ravines and possessing significant areas of swamps and forests that restricted military movement. Its most important hills reached heights over , allowing for improved artillery defense. In 1943, the area was for the most part covered with pine and mixed forests and thick bushes.
Numerous rivers also passed through the area, the most important of them being the Donets Basin, Western Dvina, Dnieper, Desna, Volost' and Ugra rivers. The Dnieper is by far the largest of them and strategically most important. The surrounding wide, swamp-like areas proved difficult to cross, especially for mechanized troops. Moreover, like many south-flowing rivers in Europe, the Dnieper's western bank, which was held by German troops, was higher and steeper than the eastern. There were very few available bridges or ferries.
Transport infrastructure.
For the Soviet troops, the offensive was further complicated by a lack of transport in the area in which the offensive was to be staged. The road network was not well developed and paved roads were rare. After rainfall, which was quite common during the Russian summer, most of them were turned into mud (a phenomenon known as "rasputitsa"), greatly slowing down any advance of mechanized troops, and raising logistical issues as well. The only major railroad axis available for Soviet troops was the Rzhev-Vyazma-Kirov line.
The Wehrmacht controlled a much wider network of roads and railroads, centered on Smolensk and Roslavl. These two cities were important logistical centers, allowing quick supply and reinforcements for German troops. By far the most important railroads for German troops were the Smolensk-Bryansk axis and the Nevel-Orsha-Mogilev axis, linking German western troops with troops concentrated around Oryol.
As part of the Soviet planning the German railroad communications were attacked by the partisans during the conduct of Operation Concert, one of the largest railroad sabotage operations of World War II.
Opposing forces.
Soviet offensive sector.
In July 1943 the Soviet front line on this part of the Eastern Front was a concave with a re-entrant around Orel. The re-entrant exposed the Wehrmacht to flank attacks from the north but the main attack carried out on the Kalinin and Western fronts would be quite difficult. 
The Western Front had assigned for the operation the 10th Guards Army, 5th Army, 10th Army, 21st Army, 33rd Army, 49th Army, 68th Army, 1st Air Army, 2nd Guards Tank Corps, 5th Mechanised Corps, 6th Guards Cavalry Corps. The Kalinin Front would have for the operation the 4th Shock Army, 39th Army, 43rd Army, 3rd Air Army, and the 31st Army.
German defenses.
As a result of the shape of the front, a significant number of divisions of Army Group Center were kept on this part of the front because of a (quite legitimate) fear of a major offensive in this sector.
For instance, at the end of July 1943, a German staff briefing stated:
On the front... held by the Army Group Center many signs show a continuous preparation to a yet limited offensive (Roslavl, Smolensk, Vitebsk) and of a maneuver of immobilization of the Army Group Center...
The front had been more or less stable for four to five months (and up to 18 months in several places) before the battle, and possessed geographical features favorable for a strong defensive setup. Thus, German forces had time to build extensive defensive positions, numbering as many as five or six defensive lines in some places, for a total depth extending from .
The first (tactical or outer) defensive zone included the first (main) and the second defense lines, for a total depth of , and located, whenever possible, on elevated ground. The main defense line, deep, possessed three sets of trenches and firing points, linked by an extensive communication network. The density of firing points reached six or seven per kilometer (0.6 mi) of front line. In some places, where heavy tank attacks were feared, the third set of trenches was in fact a solid antitank moat with a steep western side integrating artillery and machine guns emplacements. The forward edge of the battle area was protected by three lines of barbed wire and a solid wall of minefields.
The second defense zone, located about behind the outer defense zone and covering the most important directions, was composed of a set of firing points connected with trenches. It was protected with barbed wire, and also with minefields in some places where heavy tank offensives were anticipated. Between the outer and the second defense zones, a set of small firing points and garrisons was also created in order to slow down a Soviet advance should the Red Army break through the outer defense zone. Behind the second zone, heavy guns were positioned.
Finally, deep behind the front line, three or four more defense lines were located, whenever possible, on the western shore of a river. For instance, important defense lines were set up on the western side of the Dnieper and Desna. Additionally, the main urban centers located on the defense line (such as Yelnya, Dukhovshchina and Spas-Demensk) were reinforced and fortified, preparing them for a potentially long fight. Roads were mined and covered with antitank devices and firing points were installed in the most important and tallest buildings.
First stage (7–20 August).
Main breakthrough.
After a day of probing, the goal of which was to determine whether German troops would choose to withdraw or not from the first set of trenches, the offensive started on 7 August 1943 at 06:30 (with a preliminary bombardment starting at 04:40) with a breakthrough towards Roslavl. Three armies were committed to this offensive: the 5th Army, the 10th Guards Army, and the 33rd Army.
The attack quickly encountered heavy opposition and stalled. German troops attempted numerous counterattacks from their well-prepared defense positions, supported by tanks, assault guns, and the fire of heavy guns and mortars. As Konstantin Rokossovsky recalled, "we literally had to tear ourselves through German lines, one by one". On the first day, the Soviet troops advanced only , with all available troops (including artillery, communications, and engineers) committed to battle.
Despite violent Soviet attacks, it quickly became obvious that the three armies would not be able to get through the German lines. Soviet commanders decided therefore to commit the 68th Army, heretofore kept in reserve, to battle. On the German side, three additional divisions (2nd Panzer Division, 36th Infantry Division, and 56th Infantry Division) were sent to the front from the Oryol sector to try to stop the Soviet advance.
The attack resumed the following day with another attempt at a simultaneous breakthrough taking place further north, towards Yartzevo. Both attacks were stopped by heavy German resistance. In the following five days, Soviet troops slowly made their way through German defenses, repelling heavy counterattacks and sustaining heavy losses. By feeding reserve troops to battle, the Red Army managed to advance to a depth varying from by 11 August.
Subsequent attacks by the armored and cavalry forces of the 6th Guards Cavalry Corps had no further effect and resulted in heavy casualties because of strong German defenses, leading to a stalemate.
Spas-Demensk offensive.
During the Spas-Demensk Offensive Operation (Russian: Спас-Деменская наступательная операция) in the region of Spas-Demensk, things went better for the 10th Army. The Wehrmacht had fewer troops and only limited reserves in this area, enabling the 10th Army to break through German lines and advance in two days.
The 5th Mechanized Corps, relocated from Kirov and committed to battle in order to exploit the breakthrough, failed in its mission, mainly because a poorly organized anti-aircraft defense enabled Luftwaffe dive bombers to attack its Valentine tanks with some impunity. The corps sustained heavy losses and had to pull away from combat. Soviet troops eventually advanced a further as of 13 August, liberating Spas-Demensk.
Dukhovshchina offensive.
As ordered by the Stavka (the Soviet Armed Forces Command), the Dukhovshchina-Demidov Offensive Operation near Dukhovshchina started almost a week later, on 13 August. As on other parts of the front, the 39th Army and the 43rd Army encountered serious opposition. During the first day alone, Wehrmacht troops attempted 24 regimental-sized counterattacks.
Soviet troops managed to advance only over the next five days and, although they inflicted heavy casualties on Wehrmacht troops, their own losses were also heavy.
Causes of the stalemate.
By mid-August, Soviet operations all along the Smolensk front stabilized. The resulting stalemate, while not a defeat "per se", was stinging for Soviet commanders, who provided several explanations for their failure to press forward. Deputy Chief of General Staff General A. I. Antonov reported "We have to deal both with forests and swamps and with increasing resistance of enemy troops reinforced by divisions arriving from Bryansk region" while Marshal Nikolai Voronov, formerly a Stavka member, analysed the stalemate in his memoirs, publishing what he saw as the eight primary causes:
With all these factors considered, Voronov demanded that the 4th Tank Army and the 8th Artillery Corps be transferred from the Bryansk Front and committed to support the attack near Smolensk.
The stalemate was far from what had been desired by the Stavka, but it had at least one merit: it tied down as much as 40% of all Wehrmacht divisions on the Eastern Front near Smolensk, making the task for troops fighting in the south and near Kursk much easier. The Stavka planned to