The theory argues, and empirical evidence shows, that "intersections" among spheres of influences—when one state seeks to expand control over the domains of another state—inevitably fuel prevailing hostilities and reinforce an emerging dynamics of military competition that historically has led the well known phenomenon of arms race. Here the theory draws on four important concepts in international relations theory broadly defined. These are the "conflict spiral" (such as Holsti 1972); and the "arms race dynamics" (pioneered by Richardson 1960a); and the "security dilemma" (notably Herz 1950, Jervis 1997).