Rubicon

Rubicon was a ballistic launch override protocol designed by A.R.G.U.S. to prevent any country, including the United States and other NATO members, from firing a nuclear missile.

Overview
Rubicon was created as a failsafe against nuclear Armageddon. It consisted of a program and a device that stored it. The device was originally stored in A.R.G.U.S. headquarters, until Shadowspire tried to steal it. For safety purposes, the device was placed under director Lyla Michaels's skin in form of a subdermal implant.

Rubicon was designed to be "unhackable", using Fourier protocols to ensure its security. Rubicon would also know whether the missiles would launch or not, worldwide. In case of a security break, the program would continue trying to send launch codes to all nuclear missiles, one by one, whether to deactivate them or, after being reprogrammed by H.I.V.E., to ensure the launch's success.

History
Rubicon was part of Damien Darhk's plan to ensure the nuclear devastation of the whole planet, leaving H.I.V.E. as the only force capable of rebuilding it and "starting life anew". Using his dark powers, the terrorist leader ripped the subdermal implant from under Lyla's skin and brought it back to his organization. H.I.V.E.'s own scientists managed to reprogram Rubicon, so that instead of deactivating nuclear weapons, it would launch them on different targets across the world, including the metropolis of Monument Point and its suburb, Havenrock, located in Virginia, United States.

Lyla contacted Team Arrow to help stop Darhk's plan. Felicity Smoak and her father, Noah Kuttler, were instrumental in shutting down Rubicon, however, due to the program's ability to recognize the error and send launch codes one by one, a single nuclear missile was launched from Russia that destroyed the town of Havenrock, with tens of thousands casualties, that ended up fueling Damien Darhk's dark magic abilities.

Behind the scenes

 * The idiom "Crossing the Rubicon" means to pass a point of no return, and refers to Julius Caesar's army's crossing of the Rubicon River (in the north of Italy) in 49 BC, which was considered an act of insurrection and treason against the Senate of Roman Republic. Julius Caesar uttered the famous phrase "alea iacta est" (the die is cast) as his army marched through the river. In this case, Rubicon refers to the event of nuclear war, in which A.R.G.U.S. would use the device to deactivate all nuclear weaponry on the planet.