Rise of the wheeled tanks...

Japanese Maneuver Combat Vehicle

Italian Centauro II

I just had a "force of connection".  While I have yet to hear an explanation of why fighting in mega cities will be worth the high casualties, protracted conflict, and the impossibility of actually accomplishing a military objective it seems that everyone in our Defense Dept is onboard that train.

With that being the case then the way we think about armored vehicles and especially tanks will shift.

What I'm saying in a drawn out fashion is that we're about to see the rise of the wheeled tanks.

Why?

Think about it.  We've already reached a point where kinetic weapons can penetrate anything on the battlefield.  Even RPG-29's have been shown to penetrate weak points on the M1 Abrams (cool your jets...it was once classified but is in the open now).  So with that being the case what is the answer?  Lighter weight (not that 40 tons is light), higher mobility on roads (remember mega cities are not rural locales) and massive guns to deal with
enemy fortifications.  What will be the protection values?  Probably armored to deal with medium caliber cannons (talking probably proof against 30mm up to 40mm in the future), equipped with APS (to deal with infantry ATGM) and able to deal with IEDs.  What will be the caliber gun?  I'm not sure yet.  We see a couple with standard 120mm cannons.  The future might see an evolution toward even larger caliber guns designed to destroy buildings, fortifications etc.  Think along the lines of the WW2 Sturmtiger but with a turret and of course advanced ammo.

This is of course speculation but we're seeing trends that indicate that planners are seeing the battlefield in a different way.  Away from the countryside and unfortunately in the city.