I think this article is interesting, in the context of Battletech. One of the core premises behind the rise of Battlemechs was the development of advanced armor that rendered mid-late 20th century armor "primitive", and which allowed survivability of armored vehicles to improve by a nearly exponential standard, compared with a more linear advancement in weapons technology. The idea that what our state-of-the art is now could be replaced by much more efficient microstructures is an intriguing one.
Fusion power - works, additional work is needed to make it efficient.. further to make it portable Nanomaterials - work under way, eventually we will be able to make material strong enough to support a space elevator, so that sort of material would likely make some tough fighting machines Those two things alone, once developed enough, will lead to two things: 1) We could build a mech - and it could be useful due to its superior mobility over tanks and traditional vehicles, it could also survive punishment 2) Portable fusion & nanomaterials cost more than strawberries - so at any time there would be limited number of them, but if they were good enough and worth the price, everyone would try to have a number of them
