Suppose that as a consequence of two smaller countries going full nuclear, half the world supported one side, and the other half the other, but thanks to the optimal strategy mathematicians on the centrally planned side, escalation to M.A.D. was held off by some sort of compromise including diplomatic handover of secret plans to make such things as internet modem-routers without the backdoor flaw used to read those by the cleptocratic oligarchy on the other side.  So six years on, we have two branches of the internet which mainly keep off one anothers' proprietary hardware on pain of getting bitten by the automated intrusion deathword dispensers which both sides managed to hide in immutable parts of designs passed to one another at the time of the great crisis.  In that situation of there being an Eastnet and a Westnet which cannot be linked, I think that each half would continue from the blockchain, but only doing transactions within its own half.  If ever the two blockchain forks could see one another, the shorter one would get annulled by the longer one, so both forks would need an extra twelve lines of code to formally hardfork and diverge to two branches from the blockchain of satoshi.  No doubt the oligarchs would assert that since there are more transactions going on and slightly more blockchainlength in their fork, the genuine productivity improvement payments and strictly truthful advertising signature campaigns on the other side should get annulled for being less profitable ... and so a new cold war and a world of daring physical intrusion in novel stealthcopters and other unheard off new vehicles becomes possible, for those heroes of the optimal path who have been given orders to introduce a hard fork against the wishes of the rich people on the other side.  To get those twelve lines into the other side's uᴉoɔʇᴉq nodes is a prerequisite step so that opening the new berlin wall and going to world peace and prosperity will not annihilate all the bitcoin earned from genuine productivity improvements and strictly truthful advertising.