Red Army = most effective force !

[PlasmaKrab]

The first Russian (not Soviet) tanks to use TI sights were upgraded versions of the T-90 and T-80UM series using nonstandard imagers based on the imported Catherine sensor technology (I think). SO it does look like the Soviets hadn't put much research into thermals until too late. As far as I can recall, some of the clip-on ATGM TI sights were based on domestic technology, but with the fall of the USSR, the service schedule turned out to be much the same.
The last generation of Soviet tanks (T-64B/72B/80B & T-80U) used much-upgraded night sights with cascaded image intensifier and active IR converted (shorter wavelength than TI), which were way cheaper than Western thermals and quite possibly better than represented in the game regarding range and resistance on obscurants (don't quote me on this though).