What would happen if a portion of the Bitcoin network was separated from the rest of the network? Yesterday I asked a question over at SuperUser, so that I could have my facts straight before asking this question.  The scenario sets the basis for this question.

Regarding bitcoin, what would happen to the Bitcoin system if a portion of the world had it's internet connection severed with the rest of the world.  In other words if, say, all outside communication was lost in the region of Armenia, would the Armenian Bitcoin users, who continue to use Bitcoin, ultimately create a forked block chain?

If so, what would happen to the blockchain when connection to the severed region of the world is restored, and the segregated network is resolved to the primary network?

I imagine the outcome would be similar to a 51% attack.  Is that correct?
When bitcoin client downloads two conflicting blockchains, in other words when fork happened, it chooses the longer blockchain as valid, and the shorter becomes invalid and called "orphan blocks". "Length" is calculated as total combined difficulty of that chain, not number of blocks. Wiki: Block Chain

So in your scenario, Armenia most likely has less hashing power then the rest of world and it would produce shorter fork of blockchain, therefore it would be overrided after connection is restored.

51% attack implies coordinated effort from a small group of people with malicious intent, which is not the case according to your scenarion, therefore I wouldn't call 51% attack.

It would be easy to counter any negative outcome because users of isolated network would know instantly about the problem from sudden drop of total network hash power, and would just need to avoid spending bitcoins until connection is restored.