Ok, so to describe a history of NATO and USSR MBT's during Cold War and beyond.
In 1960's NATO started to field new tanks in their inventory, lightly armored but well armed and very mobile Leopard 1 and AMX-30, and better protected, with similiar firepower and lower mobility, the M60 and Chieftain. At that time the basic medium tank of USSR and WarPac was T-54 and it's upgrade the T-55. In the same time Alexander Morozov abandoned work on all tanks manufactured back then in USSR and started to work on new revolutionary tank, this tank was T-64. Of course T-64 development history is long and very interesting, but I do not have time to write about it here right now.
So during 1960's Soviet Union have a medium tank (only ~38 metric tons weight) that is more mobile, better armored and better armed than anything else used around the world.
From T-64 evolved simplified T-72, that was seen as mobilization tank and tank for all allies of soviet union, while T-64 was exclusive only for USSR armed forces.
And there was a third tank based on concept of T-64 but, again different, intended mainly as analog to old heavy breakthrough tanks, the T-80.
All of these T-64, T-72 and T-80 were based on the same general design concept, but where different in details, mechanical components etc.
Of course each of these designs evolved.
T-64A recived for example powered cupola with ability to fire commander machine gun from the inside. T-64B recived modern digital fire control system, and guided ammunition in form of gun launched anti tank guided missile, T-64 series also had the most advanced and promising engine from all soviet tanks, the 5TD. T-80B recived the similiar fire control system as T-64B, but used GTE and had simpler commander cupola.
T-72 series were for the most time simplified tanks, untill more modern T-72B with better protection than T-64B and T-80B was fielded, still T-72B had inferior fire control system.
But all these were seen as outdated by soviet armed forces, and more modern tanks based on T-80 were designed, the gas turbine powered T-80U, intended as replacement for T-80B, and T-80UD powered with advanced diesel 6TD (further development of 5TD), in general more advanced than T-80U, and intended as T-64B replacement.
NATO untill 1979-1980 didn't had anything capable to stand against these tanks. But in these mentioned years, FRG fielded first Leopard 2's, and USA first M1's, while in 1983 UK fielded first Challenger 1.
In general overview for the most of the ending years of the cold war, NATO and USSR was head to head in tanks design, however there was one advantage that NATO had.
This advantage was lack of heavy restrictions on tanks size and weight, this allowed NATO tank designers to incorporate composite armor, where there was far more space in armor cavity for composite armor filler. Also using mostly welded structures, allowed for far more easier composite armor impementation.
This gave NATO advantage in composite armors, however price for it was weight well over 55 tons, in fact in 1988 the M1A1HA was approx ~60 metric tons heavy, Leopard 2A4 was not much lighter either.
Soviet tank designers were perfectly aware that within very strict size and weight limits (tanks weight could not grow over 50 tons), they will be not capable to increase vehicles protection by increasing space for composite armor filler in vehicles armor cavieties (even if overall armor thickness was similiar in NATO and Soviet designs).
So by early 1980's most tanks were equipped first with relatively simple Kontakt-1 ERA as a messure to increase protection against HEAT, and by mid to late 1980's, some tanks variants recived heavy (universal) Kontakt-5 ERA capable also to increase protection against APFSDS ammunition.
This gave time for soviet designers, unfortunetly for them by the second half of 1980's, NATO tank designers were not only using advantage of more composite armor per whole armor thickness, but also were working on use of advanced materials and heavy metal alloys in armors, while the Russian and Ukrainian tank designers, mostly focused on further development of ERA.
This ended with a very interesting situation where NATO countries are developing more and more advanced composite armors, while Russia/Ukraine is developing more and more advanced ERA while it seems that there is limited focus on more advanced composite armors development there at that moment.
So in fact the best NATO designs, and best Russian/Ukrainian designs, have comparable protection, but achieved by different means, and with different results.
NATO have more advanced composite armors with multi hit capability, but the price is more weight and bigger size.
Russia/Ukraine have more advanced ERA designs, but these are only single hit protection messures, while their composite armors seems to be slightly less advanced, however the advantage of such design is less weight and vehicle smaller size.
Ok, this is only a simplified description, so do not treat it as something far from reality, I could wrote the whole damn book about this subject, and probably single book was too small to bring whole knowledge about this subject.
You know - my friend take a part on VictorStrike2000 and 2001 in Drawsko Pomorskie trening center in Poland.
During this trening fight (whit using MILES system) american regiment Ah-64A + OH-58 Kiowa where coopereting whit MLRS battery. The target was polish air defence using non-downgraded SA-8M Gecko (now Sting" SA-8P Sting ADMS Air Defence Missile System) And what? And US fools lose whole AH-64 regiment during polish AA ambush. And thanks to not using radars in long mode (only short for directing) and very quick change of position Sa-8 lost only 2 complex for MLRS battery fire. Quite low when we consider the fact that US army "lost" in this MILES battle more then 30 Ah-64...
In next year "battle" where repeated - This time with ridiculous restrictions for Sa-8Gecko battery (fire range limited to max 2km, no using radars, 2times shorter time for MLRS battery countrfire) and what? ~4-6 Sa-8 lost and... 16 Ah-64 "killed" in this MILES battle.
And in both cases Ah-64 regiment whit MLRS COOPERATION was not able to destroy the target (mechanizated batalion). The Sa-8P not guilty Ah-64 regiment near target area. The Ah-64 was not able to using weapons because there was not able event to approach near target.
The key was using terrein for ambush and using non advanced posoration system (ex: microwave on jeep, or a small motor connected to the radio station). This, and well-trained Sa-8 crews was enought to "destroy" Ah-64 regiment during first battle, and stopduring second. In both cases the target was not destroyed becouse Ah-64 regiment was not able to attack near target area.
And old Sa-8 is not Tor... It's not only example when even polish slighty downgraded WarPac AA was better then USarmy image...An there was more suprises - ex the same time to "Fire task" fo MLRS battery and... polish BM-21 GRAD battery (using Topaz system).
Americans made during these excerices several mistakes.
They did underestimate their enemy, lack of proper recoinassance, lack of ground troops to provide additional support.
This also shows vurnability of attack helicopters, the same mistakes were repeated in Iraq, where AH-64's were stopped by Iraqi heavy machine guns and light anti aircraft automatic cannons fire.
Well, surprisingly in all wars, air forces have such problems, while ground forces with APC's, IFV's and MBT's even despite losses, can achieve their tasks.
BTW I read several good articles and books about what happend in Iraq in 2003. What American tank crews were doing back then... some things are just incredible. So before anyone will say that tanks are not needed, I can say, and not me, but also soldiers fighting then and there, that without tanks, many more casualties could have been taken by US forces, and probably many tasks could have not been accomplished.
