Model. As a result of this split, the Soviets had cut the main supply lifeline of Army Group South, the Lviv–Odessa railway. Now, the southern group of German forces would have to use the long roundabout route through the Balkans, with all of the supplies being rerouted over the Romanian railroads, which were in poor condition. Background Throughout February, main forces of the 1st Ukrainian Front repulsed heavy blows from the units of the 1st Panzer Army in their attempts to de-blockade the trapped German forces at the Korsun-Cherkassy Pocket. At the same time, the right wing of the 1st Ukrainian Front had executed the Rovno–Lutsk offensive, spearheaded by 2 Cavalry Corps. In the course of that operation, a new bulge was created, in which the Soviets dangerously hanged from the north over the 1st Panzer Army and the rest of the Army Group South in Ukraine. It would be there, in the Shepetivka area, where Soviets will shift their main weight of attack. By striking south from that area towards the Dniester river, the 1st Panzer Army and all German forces operating in the right-bank Ukraine would be cut off from Germany and pressed against the Carpathian Mountains. Furthermore, the Ternopil–Khmelnytskyi railway junction, which was part of a wider Lviv–Odessa railway, was a major German communication and supply center that linked together northern and southern portions of Army Group South. It was also the last railroad before the Carpathian Mountains. If this railroad was cut, the southern group of German forces would have to use the long roundabout route through the Balkans, with all of the supplies being rerouted over the Romanian railroads, which were in poor condition. Soviet preparations On 18 February 1944, immediately after the end of the Battle of the Korsun-Cherkassy Pocket, the 1st Ukrainian Front received the task of carrying out a new offensive operation, which is known as the Proskurov-Chernovtsy Operation. The 1st Ukrainian Front front had at its disposal the 13th, 60th, 1st Guards, 18th and 38th Combined-Arms Armies, 3rd Guards, 1st and 4th Tank Armies, 2nd Air Army, 4th Guards and 25th Tank Corps, 1st and 6th Guards Cavalry Corps. The directive of the Supreme High Command (STAVKA) for this operation stated: "To prepare an offensive with the inclusion in the composition of the strike group of the front the troops of the 13th, 60th, 1st Guards Armies, 3rd Guards and 4th