Аннотация:A main goal of the paper is to discuss the world telecommunications strategy in transition to the IP world. Particularly, we analyze the parallels between emergency and military services and co-existence of circuit switching and packet switching technologies. We discuss the difficulties to build the emergency networks in the U.S. and Russian Federation. As a case, we are passing through three generations of American military communications: (1) the implementation of signaling protocol SS7 and Advanced Intelligent Network, (2) transformation from SS7 to IP protocol and, finally, (3) the extremely ambitious cybersecurity issues. In conclusion, recalling the difficulties that complicate the transition from circuit switching, seems, it is timely to say: the long circuit switching CS and packet switching PS coexistence seems inevitable.