[quote=@MetalLover]
<Snipped quote by Iluvatar>

Just one nitpick, I stated that the earliest you can be out of the Bunker is 2260, other then that it is great.
[/quote]Why? There's nothing really which truly neccessiates dormancy for this long.
Sure, even with clean nukes there are issues like a potential ice age from the dust generated by massed us of kinetic rod orbital weapons. Somebody can be also deliberately asshole by using dirty nukes to fuck their enemy over. But in that case if they want they can make that part uninhabitable for even millions of years.

Pardon me if you perceive this as nitpicking but I just give you ideas. I can understand that you don't wish to give people unfair advantage by starting sooner but perhaps there's no such gain to begin with. A nation with longer surface-dwelling history can be as good as the others. Or even worse. The don't be OP ruling applies on them regardless.