"In Paul Baran of the published, "On Distributed Communication Networks" in which he formulated the concept of packet-switching networks having no single outage point. With these theoretical concepts in place, others could develop workable concepts. Two additional key elements, re-routing around outages and access by other networks, helped lay the necessary groundwork to create the theoretical basis for the inception of an Internet. The underlying motive for developing this technology was to streamline communication between military command centers, remote missile bases and other installations in the event of a preemptive nuclear attack. DARPA funds for developing packet switching in the late accounted for 60% of the computer research done in the United States at that time. Much of the concern during this period of the cold war was based upon a study done by the RAND Corporation that cited the lines of communication as the most vulnerable portion of U.S. military command."