Should somebody atempt to build one ?

Nuclear powered, capable to carry jets and cruise missiles...

Not sure that even a big spender like the US military would be crazy enough to pour all that money into a flagship like that.

But with the Cold War 2, opposing the US and EU on one side and China and Russia with it's pet states, on the other, a weapons system able to fly quickly around the world, and wreak havoc, in certain hotspots, could prove valuable.