You say that the modern MBT now weighs 60+ tonnes, but that only applies to Western MBTs. The T-72 by contrast only weighs around 45 tons (the same as a Panther), and the T-90 similarly hovers at a similar weight level. The latter in particular is widely seen as a peer competitor of the M1Abrams, with similar levels of armoring (albeit the use of classified ERA or composites materials by both sides means we will never know for certain which tank actually has better armor), a gun just as big and powerful, and moves just as fast. "Bigger" is in fact not necessarily "better".
There is actual data on the tanks out there,
it was even compiled into a nice, easy to see image. Overall, the T-90 only has superiority to the M1 Abrams. The M1A1 has comparable armor (and thats including the reactive on the T-90) and a far superior main gun. The M1A2 is just superior across the board. Note that the Russian arms industry suffered enormously with the fall of the Soviet Union.
Assuming that all 'Western' MBTs are exactly the same is just plain wrong. Aside from the fact that Western MBTs varied enormously during the Cold War, you had the British with heavily armored, slightly slower Centurions, the Germans and French with their fast, lightly armored Leopard 1s and AMX 30s, then the Americans whom had middle of the road Pattons, although the Pattons had a particular emphasis on hull down tactics and had armor layouts to reflect that. Even to this day you have the Israeli Merkava IV which is so out of left field that even Russian tank designs have more in common with Western tanks than it.
Then you have the Type 90 (Japan) at 50 tonnes, the Arjun (Indian) at 60 tonnes, the K2 Black Panther (South Korea) at 55 tonnes, and the Type 99 (PRC) at 60 tonnes. Infact, the only non-Russian tank that has 45 tonnes as its weight is the Chinese/Pakistan export tank, the MBT-2000/Al-Khalid.
Overall, theres a lot of basis on my assertion that the average is 60 tonnes. Note that the newest model of Abrams are clocking in at 70 tonnes.
Secondly, the idea that the Western MBT is a balance of speed, armor, firepower, and reliability is one of the most well-repeated pieces of marketing-speak by BAE and other tank manufacturers, but in reality is pretty nonsensical because people are not looking at the doctrine that created the Western MBT. In reality, the Western MBT is actually a specialist anti-tank vehicle - it was meant to take on the hordes of Soviet tanks in the inventory of Group of Soviet Forces Germany. This is why its main gun only really has ammunition suitable for destroying armored vehicles, as opposed to a much wider array of ammunition available for the 105mm L7 of the M60 Patton. This is why its armor is meant to defeat 125mm tank rounds, not dinky RPG-7s carried by your regular Taliban or Iraqi insurgent.
Russian/Soviet tank designs are not much different, and infact are even worse against infantry due to their poor gun depression and autoloader increasing difficulty of ammunition swaps. The only MBT thats specifically designed against infantry threats is the Merkava IV, which is why it is a radically different design than Western or Russian MBTs.
They actually aren't terribly reliable outside of the West German plains and are extremely logistically intensive - which is why the Abrams was essentially withdrawn from combat in Iraq in favor of lighter vehicles like the Stryker once all of the Iraqi T-72 Divisions had been destroyed. Only for intense urban combat scenarios were the Abrams ever deployed again - and even in these situations specialized Urban Warfare kits were developed as the Abrams doesn't even have basic infantry-armor coordination kit like a plug-in set for a telephone so that the infantrymen could talk to buttoned-up tank crews.
The Abrams issues are entirely due to the gas turbine, which is why the Russians abandoned their gas turbine tank (T-80) and there is a lot of talk about switching the M1 Abrams over to a diesel. Other western tanks like the Leo 2 are known to be rock solid reliable.
The Panzer Division, contrary to popular belief, was never meant to be the primary anti-tank component of the German army in the Second World War. Those who contest this are unaware that the Germans had an entirely different set of units that were meant to perform anti-tank work - the "Panzerjaeger" - of which one abteilung (battalion) was present in every first-class German infantry Division and efforts were made to have one even in the Volksgrenadier outfits.
Kind of curious you make that assertion considering the Panther was specifically designed to counter the Russian KV-1 and T-35. The Panther was meant for tank killing, and although it could support infantry fairly well, to boot. The only amazing anti-infantry tank was the Tiger, ironically, its 88mm gun was more suited to anti-infantry warfare than anti-tank warfare, and its thick front and side armor meant that normal infantry anti-tank weapons of the time would not have been able to penetrate it. I would not be suprised if the Tiger's infamy was primarily due to the allied Infantryman's contact with it.
Finally, the idea that the T-34 or Sherman went obsolete after the war is false. The T-34 is in fact still suspected to be in use in some African countries, because they serve perfectly fine against enemies with no anti-tank weapon heavier than an RPG-7. The Sherman had a glorious post-war career with the Indians and Israelies. The former - using unupgraded Shermans - were instrumental in several armor vs armor engagements that humiliated the Pakistanis using M48 Pattons (a tank supposedly better than the Pershing), while the Israelis - using Shermans upgunned to a 75mm roughly equivalent to the performance of the L70s - are confirmed to have taken on and destroyed T-62 tanks at Yom Kippur. The Panther by contrast was never used as a tank by anyone but the French, as the Bulgarians used theirs as pillboxes post-war.
Your assertion is bad and you should feel bad. Just because a tank is still in use does not mean it is not obsolete. The T-34 and M4 Sherman are still in use even today in some third world backwaters, they are still obsolete. The Sherman became obsolete with the introduction of the M26 Pershing in 1945, and the T-34 became obsolete with the introduction of the T-55, also in 1945. The Americans and Soviets quickly phased the Sherman and T-34 out and that was the end of that. Bringing up examples of the Israelis using Shermans is kind of silly considering that the Israeli army was using -anything- it could get its hands on in 1955, remember that the Israeli state was barely even formed and the Israeli arms industry was nonexistant at this time. The tanks were phased out when the Israeli arms industry was able to establish itself and the Israelis were able to replace the Shermans with far more capable designs.
Note that even the worst opposition the Israeli shermans faced were T-55s and T-62s, and the Shermans still needed HEAT rounds to penetrate. This is in spite of the fact the tanks were upgunned to 105mm Model F1s.
PS: Note that the Israelis had serious problems with the Sherman's reliability due to the added weight of the upgraded guns putting too much strain on the engine and suspension.
It's actually ridiculously and childishly easy to just say "Bigger gun! Bigger armor!" which is precisely what happened with the Panther due to Hitler's meddling.
That was the Tiger. The Panther was actually an attempt to address the shortcomings of the Tiger, primarily the high cost and low production rates, while keeping the anti-tank capabilities. Of course, the primary casualty of the cost-cutting was the reliability.
In reality, it takes engineering skill to fit as much capability into a 45 ton chassis; which should be apparent even in the context of the Second World War when the Soviet IS-2 has the same weight, has a much larger gun (capable of killing Tiger IIs with frontal hits), better armor, similar mobility, and much higher reliability.
The IS-2 could only penetrate the Tiger II from the front by shooting 3-4 times at the welding at point blank range.
No offense, but a lot of your arguments are based on bad information.
The IS-2 was absolutly horrid at anti-tank warfare. Its main gun was primarily designed for infantry support and its front armor was not much better than the Tiger I. The Tiger 2 was heavier, but it had a far better gun and far more armor.
