Network partition resistance
For the Bitcoin network to remain in consensus, the network of nodes must not be partitioned. So for an individual node to remain in consensus with the network, it must have at least one connection to that network of peers that share its consensus rules. This document describes how we attempt to achieve this.
We can't rely on inbound peers to be honest, because they are initiated by others. It's impossible for us to know, for example, whether all our inbound peers are controlled by the same adversary.