A look back: Janus, a conflict simulation model

In 1981, a select group of U.S. Army officers visited Lawrence Livermore National Laboratory to ​​​​​​​participate in a series of nuclear wargames unlike any conducted. Instead of plotting battlefield maneuvers and scenarios on sand tables, as had been used well into the 1970s, these officers were placed in front of display screens to use the world’s first near-real-time, player-interactive combat simulator – Janus.

Livermore’s involvement in combat simulation was born in the early 1970s, when Lab scientists, under the leadership of D-Division’s Don Blumenthal, began studying the battlefield usefulness of recently developed tactical nuclear weapons. Then current analytical methods didn’t take into effect variable “fog of war” factors, and a model that could graphically portray the potential uses and ramifications of these weapons was needed.

In 1974, Laboratory researchers began developing a high-resolution combat simulation model named Jeremiah that ran on a CDC-7600 mainframe. Jeremiah wasn’t interactive, and orders to units were scheduled and provided as input to the simulation. However, in 1978, a major advance occurred when the Lab’s George Smith developed the Mini-J, the first two-sided, player-interactive simulation model designed for a stand-alone computer system. Building on the success of this revolutionary model, LLNL’s Conflict Simulation Laboratory, a year later, introduced Janus – an improved two-sided, interactive conflict simulation program named after the two-faced Roman god.

Written in FORTRAN and running on the new VAX 11/780 minicomputer, Janus featured player input and output using an interactive graphical user interface. Often compared to one of the earliest developed video games, “Pong,” Janus allowed two team commanders, a blue and red team, housed in separate rooms to simulate combat on high resolution video screens depicting a realistic digitized battlefield map with moveable, changeable icons.

Based on the success of D-Division’s new combat simulation Janus model, the U.S. Army’s Training and Doctrine Command signed a working relationship with the Lab in early 1981 to further develop combat simulators, laying the groundwork for the first trial run by a select group of officers that year. Army officials planned to use the $2 million Janus system, housed in Bldg. 111, to learn how allied combat forces might cope with an attack by an enemy using every modern weapon, including nuclear weapons, as well as how friendly forces could repel such an attack through conventional forces and last resort small tactical nuclear weapons. The Department of Defense believed that the Janus program would be able to train these and future officers to think more clearly about the costs and benefits of battlefield strategies

According to D-Division Head Blumenthal, these were certainly among some of the lessons learned by the Army visitors, as the tendency among even veteran officers was to “retrieve the battlefield with nuclear weapons” when caught out of position. One officer who let his position deteriorate reached into his arsenal to employ higher-yield weapons that destroyed not only the enemy troops, but also wiped out his own troops. “The rapidity of causalities surprised them all,” according to Smith, as he observed the officer’s reaction, a subdued “holy smoke,” to his battlefield decision.

In 1983, the Lab transferred this early version of Janus to the Army, while it continued to refine it. In the mid-1980s, the program was upgraded and made more flexible, incorporating higher-resolution graphics, distributed processing and real-time play with much larger forces and greater variety of combat systems. In 1989, the Army used Janus as an operational planning tool, prior to the invasion of Panama (Operation Just Cause) to overthrow dictator Manuel Noriega. Battalion and company leaders of Operation Just Cause later related that they felt the war games helped save lives. Janus also was used a year later for Operation Desert Storm planning and was officially turned over to the Army in 1991.

Over the years, various iterations of the Conflict Simulation Laboratory’s systems have been created and widely used by several government agencies. Today the culmination of this work is the Joint Conflict and Tactical Simulation (JCATS) model. JCATS is widely used by the Department of Defense, Secret Service and other agencies for planning and training.