In the tragic days of August 1968, the radio stations of Prague, in their last instants of freedom, transmitted the hallucinating chronicle of events that nobody would have considered possible in the Europe of the sixties, twenty-three years after the end of the last world war. But in the first hours of the morning the Praguers had seen entering in the streets of their city long columns of Soviet tanks, green monsters with turrets in the shape of turtle shell and large white crosses painted on them, and long cannons which with the circular movement of the turrets seemed elephant trunks dedicated to sniffing. For the military observers the show was not new. Those tanks had been seen already in 1953 during the riots arisen in East Berlin, and in 1956 in Budapest. Actually such tanks had started their career even before, for they were descendants of the "Stalin" family of tanks, the most prestigious ones built by the Soviet Union during the Second World War.

Conceptually, the IS (Iosif Stalin) tank descended directly from the KV heavy tanks which, after having given good proof of themselves in the first times of the war, had been passed to second line just after the Germans managed to discover their defects (actually quite numerous). Because of that, engineer Kotin had designed a new tank which, starting from the hull and the mechanics of the KV, was fitted with a new turret that mounted an excellent 85-millimeter cannon. Besides, the suspension had been improved and the engine enhanced. However, this tank was produced only until the early 1944, when it was replaced by a new type fitted with a 100-millimeter cannon. Nevertheless, this new tank still was not at the level of the expectations of its projector, who would reform it until in the mid 1944 would see the light the IS-2, armed with a 122-millimeter cannon.

This tank, which would reveal itself as an excellent compromise between driving power, armor and armament, would be absolutely the best Russian tank, and surely one of the best built during the entire war. It is proof of this affirmation the fact that its design, properly updated, influenced during many years the production of Soviet tanks and, therefore, of the entire Communist Bloc. Structurally, the IS-2 was a tank with a hull obtained partly by casting and partly by welding. Its plates were specially studied to present sloped or rounded surfaces to the enemy projectiles. The engine, a V2 JS (V2K) Diesel of twelve cylinders in V and 520 horsepower, was able to move the tank on road at a speed of 37 kilometers/hour, which was not little thing considering the weight over 40 tonnes.

There were some problems with the storage of ammunitions, because, being the cannon one of 122 millimeters and separated projectile and charge, it was irremediably limited. Inside the hull there was space for 28 full rounds for the 122-millimeter cannon, the only one that could compete against the frontal armor of the Konigstiger. Of the IS-2 tank, which would remain in service (on its original form) with the Red Army until 1954, were derived many other types, from conventional self-propelled to modern missile launchers. But it seems that its last operative apparition was the one initially mentioned, in the Prague of 1968, after an infortunate intervention in the Arab-Israeli War.