The German strategic offensive named Operation Typhoon was planned to conduct two pincer offensives , one to the north of Moscow against the Kalinin Front by the 3rd and 4th Panzer Armies , simultaneously severing the Moscow – Leningrad railway , and another to the south of Moscow Oblast against the Western Front , south of Tula by the 2nd Panzer Army , while the 4th Army advanced directly towards Moscow from the west .