Jim Strickland wrote: Packet-switching was invented by Paul Baran to provide a communications system that could survive a nuclear war. IP is in principle is capable of being used to implement such a system. However, there is nothing in IP that guarantees that an IP-based internet will in fact be that robust. The Internet as actually deployed is nowhere near sufficiently robust to survive a nuclear war, or even a large-scale conventional war. While there may not be single failure points that would be catastrophic, it would not take the destruction of a very large percentage of backbone routers to take it down. By "down", I don't mean a situation where no nodes can communicate with other nodes. I mean a situation contrary to the normal experience in which any node has a high likelyhood of being able to communicate with any other node. The Internet isn't useful if you can only communicate with an unpredictable subset of it. If all of the connections truly were routing peers, that would be true. But many of them aren't. If a single major peering point (or a few of them) were destroyed, the net would still function, and within days would be back to business as usual. If 20% of the peering points were destroyed, the net wouldn't be usable (in the normal sense) for quite a while, possibly weeks.