Bitcoin network splits? Alleged situation, due to X, country or geographical region Y falls off the internet map, but still has it's own network running. Blockchain splits and this situation continues for 6 months.

After 6 months there is a country specific chain, and the rest of the chain.

What happens, how can it be folded back in, does it permanently cause a chain fork, has this been considered or does bitcoin already handle this situation?
When the network rejoins, the chain with more proof of work wins. Servers on the losing chain will switch to the winning chain. Transactions from the losing chain will be recovered and mined into new blocks on the winning chain.

There are three types of transactions that can't be recovered:


Any transaction that claims a block reward cannot be recovered.
Any transaction that uses an input that is already consumed by a transaction in the winning chain cannot be recovered.
Any transaction that uses an input from a transaction that falls into either class above cannot be recovered.