Pre-World War IIIEdit
The SDI was created in 1983 by President Ronald Reagan. According to President Reagan himself, the initiative focused on strategic defense rather than the pre-existing strategic offense doctrine of Mutual Assured Destruction (MAD), of which Reagan was a vocal critic. To oversee the development of the defense project, the U.S. Department of Defense created the Strategic Defense Initiative Organization in 1984.
Popularly dubbed "The Star Wars Project" by the media, in reference to the popular 1977 science fiction movie trilogy by George Lucas, the ambitious initiative was widely criticized as being "unrealistic, even unscientific", as well as for "threatening to destabilize MAD and re-ignite 'an offensive arms race'". But no one outside of the government (and the military) knew the truth: it wasn't possible with the technologies that existed at the time. Simply put, the project was a failure.
World War IIIEdit
The SDI was briefly mentioned in a cutscene just before the U.S. mission Into The Mountains: "It soon became apparent that the Russians' next target was Fort Teller, which housed the Strategic Defense Initiative, or as the public popularly dubbed it: the Star Wars Project. What we knew - and they didn't - was that the project was a bust; that we had nothing to stop their nuclear missiles from striking our cities and military bases. We couldn't let them figure that out, so we moved east..."
Not risking the compromisation of the SDI's true nature which would have allowed the Soviets to bombard the US with nuclear warheads, the defending US forces focused all their efforts to defend Fort Teller and successfully warded off the Soviet attackers at the cost of sacrificing Cascade Falls and Captain Bannon's Company with an authorized nuclear strike.
It isn't mentioned again in the game.