Two divergences make the Soviet carrier plausible

The timeline limits Stalin's prewar battleship program to two Sovetsky Soyuz-class hulls. Concentrated resources bring Sovetsky Soyuz to launch and roughly 50 percent completion before Operation Barbarossa, while Sovetskaya Ukraina is lost after German demolition at Sevastopol. A second divergence leaves Graf Zeppelin in much better condition because Soviet forces overrun the yard before serious sabotage. Sovetsky Soyuz enters service in 1951 and the rebuilt carrier follows in 1952, both while Stalin can protect the expensive fleet program. The Soviet Navy gains two credible starting hulls, then must solve the practical problems of operating them.