Transition to war (TTW) is a North Atlantic Treaty Organization (NATO) military term referring to a period of international tension during which government and society move to an open (but not necessarily declared) war footing. The period after this is considered to be war, conventional or otherwise, but the term TTW found its origins in the peak of the Cold War as a key NATO concept within the tripwire escalation of the DEFCON status. This could include the suspension of peacetime services, closing motorways to all but military traffic and the internment of subversives without charge or trial.