Purpose of the MBT?

[Tukhachevskii]

The CKEM is another promising technology that seeks to put tank/bunker killing power into a smaller, lighter and (presumably) cheaper package.

The two technologies (AT and MBTs) seeming to be going in opposite directions. AT technologies seem to be getting smaller, lighter and cheaper while MBTs, in response to these new technologies are getting larger, heavier and more expensive. It reminds me of the problems we were having when I was in Iraq. The IEDs kept getting better and in response we kept adding armor to our HMMWVs, almost to the point of absurdity. It seems to demonstrate that lethality progresses much faster than survivability. At some point I suspect that we will reach a point where simply cannot add anymore armor to the MBT and expect it to move or expect to be able to transport it on any platform other than a ship. AT weapons, on the other hand, will continue to get better. At what point will the lethality of AT outweigh survivability of MBTs to the point of obsolescence?

Yes, but what is it they say about the defence/offense relationship...defence is always cheaper (i.e., counter-measures). ATGMs were countered by first generation active armour (or re-eactive armour) like the Israeli Blazer system. MBT protection will be vastly improved with the addition of active protection systems like LEDS as well as electric armour (which detonates/prevents detonation/initiates premature detonation[] of the missile warhead section by frying its electrics). Future systems will be capable of engaging hard core penetrators like the HVM or APFSDS penetrators (by knocking them of course rather than destroying them). The real problem are TTPs for the activation of active armour in environments of heavy force density such as FIBUA where infantry will be in intimate support. Will probably necessitate greater dispersion of vehicles in open terrain and the deployment of single vehicles well clear of infantry in urban terrain (sort of like mobile pillboxes). Consequently, I don't see future MBTs weighing as much as the monsters around nowadays (65 tonnes in some cases).