Even in the present day there are plenty of large and/or hardened targets that a B-16-12 would have trouble dealing with. And that situation is likely to only get even worse as this new Cold War progresses.
In other news:
The weapons have been built to 'threaten the United States', the commander of Washington's Pacific Fleet has said
www.telegraph.co.uk
Does the B-83 actually have a greater hard target capability than a B-61-12? I rather doubt it given a CEP measured in hundreds of meters. Reducing aim point accuracy has a logarithmic effect on peak pressure on the target. About the only thing I think it would be useful for is a very wide area target.
RNEP B83 would have combined a penetrating nosecap like MOP with a INS kit like -12.
The B83 is a LLNL design and the B61 is a LANL design, so they were two bureaus working in competition for the same specification, rather than separate specifications. It was just footdragged through multiple admins. Since LLNL lost and LANL won I suppose -12 was considered adequate for a good swathe of the classes of targets RNEP was supposed to kill. As for -12 itself, I'm pretty sure it's designed explicitly to slap launch control centers in Dobarovskiy, as a replacement for the GBU-28, more than anything, but it probably has little to no hard target penetration. Good luck knocking out the Iranian super silos or the Yamantau bunker, hope you brought enough bombs to literally excavate those targets.
For a long time the favored contender was the B83, I think because it was on the way out and it was seen as a way to "preserve" the tactical/battlefield use warheads of the B61s, rather than any true merit to the design. Since the -12's are converted from older B61s, that means fewer tactical warheads for DRF Strike Eagles to use, which is bad. However AFAIK the money that was supposed to be used for the B83 impact test was used to help develop MOP instead, because there was some controversy as to whether or not the B83 constituted an arms regulated weapon.
B-61-12 doesn't have particularly robust penetration capability anyway, it's just a INS kit and reduced yield weapon. I suspect the B83 based RNEP would have ideally been comparable to MOP in penetration depth, so about 100-200 feet into granite or something like that, but -12 is a sort of halfway house between the two. Better than nothing I guess but it would probably require multiple impacts to disable a truly deeply buried command post like Yamantau.
Some of the potential use cases studied were neutralization of chemical agent storage bunkers in Iraq, to avoid accidentally dousing US forces with nerve agents like in 1991, and destruction of superhard command posts or Iranian-style super-hard launch site/magazine/reloader...things with RNEPs from B-2s.
So yes, had the US actually constructed the RNEP, it would have been vastly superior in destruction of hard targets to the B-61-12. Given that the US has been consistently derating warheads' yields and improving accuracy I suspect -12 is mostly for hardened surface targets rather than deeply buried targets, like the W76-1, so it's an anti-silo or anti-TEL shelter weapon. The derating of the yield is less about the accuracy, and more about the warhead being ancient and unreliable in achieving its design maximum yield, so you have it backwards I think. The accuracy lets older, less reliable warheads achieve similar lethal effects despite a fizzle now and then.
Why else is -12 replacing the -3, -4, and -7, but not the -11, given the latter is a parachute retarded penetrator? Probably because the -3, -4, and -7 are twice the age of the -11s, and their warheads have degraded since then, and can't be trusted to reliably deliver maximum yield. I imagine in about 20 years we'll see a B-61-13 replacing the -11s.
Had RNEP B83 entered service I think the -12 would still exist too, but it would be less advertised as a "hard target penetrator", which is something it's being shoehorned into because MOP isn't sufficient (not unlike how F-35 is being shoehorned in to replace F-22 as a air superiority fighter), and more as a "reduced collateral damage" tactical weapon.
MOP, on the other hand, wouldn't exist if RNEP B83 had been allowed to live.
