The US projects power all over the globe, with 11 aircraft carriers, over 300 more ships, Hawaii, Guam, bases in Okinawa, Kuwait, Germany, etc. Yet, the inters

The US projects power all over the globe, with 11 aircraft carriers, over 300 more ships, Hawaii, Guam, bases in Okinawa, Kuwait, Germany, etc. Yet, the interstate system was designed to make the 48 states easier to defend in an invasion? If we're ever humbled to to point of a North American invasion, the parallels to Rome will be rich. It was only when Rome's empire faded, and they could not maintain control of their colonies, that the Germanic tribes finally sacked the Eternal City, and they were aided greatly in their invasion by an extensive road system stretching from the frontier straight back to Rome. If a humbled and bankrupt nation wants to make an invasion difficult, then it needs all the mountains and swamps it can get.