To be fair to SupCom (though maybe not WiC) we can't mount anything near that size on a ballistic missle. The Peacemaker ICBM (the one we use right now) only carries a 300 KT warhead. Sure it's enough to level any good sized city, but it certainly isn't the size of the 50 MT warhead the Russians tested. The Trident warhead is MIRV and has a total warhead strength of 450 KT. So basically, while Supcom's nukes are only about the same force as WWII era bombs, we really can only mount nukes with 10x that strength right now.