security agreements between two nations, or a multilateral exercise if the agreement is between multiple nations. Simulation Other types of exercise include the Tactical Exercise Without Troops (TEWT), also known as a sand table, map, cloth model, or computer simulation exercise. These allow commanders to manipulate models through possible scenarios in military planning. This is also called warfare simulation, or in some instances a virtual battlefield, and in the past has been described as "wargames". Such examples of modern military wargames include DARWARS, a serious game developed since 2003 by DARPA with BBN Technologies, a defense contractor which was involved in the development of packet switching, used for ARPANET, and which developed the first computer modem in 1963. Military operations and training have included different scenarios a soldier might encounter with morals and different ethics. In one military operation soldiers are frequently asked to engage in combat, humanitarian, and stabilization roles. These increase the ambiguity of a role one may encounter and challenge of ethics. This will also lead the military personnel to have to make a difficult call in challenging circumstances. Even in difficult situations and conditions, military personnel still has to follow rules and regulations such as: 1) when the right thing to do is not immediately clear; 2) when two or more important principles or values support different actions, and 3) when some harm will result, regardless of the actions taken (Defense Ethics Program, Department of National Defense, 2012). These simulations involve crude living conditions, sleep deprivations, time limit, and either lack or ambiguous amount of information. A subset of simulated exercises is the Table Top Exercise (TTX), typically limited to senior personnel stepping through the decision-making processes they would employ in a crisis, a contingency, or general warfare. History The use of military exercises and war games can be found to date back to as early as the early 19th century, wherein it was the officers of the Prussian Army who created the contemporary, tactical form of wargames that have since been more widely used and developed by other military conglomerations throughout the world. Non-tactical forms of wargames have existed for much longer, however, in the forms of tabletop games such as chess and Go. The modern use of military exercises grew out of the military need to study warfare and to reenact old battles for learning purposes. During the age of Kabinettskriege (Cabinet wars), Frederick