Collapse

"J.C. Denton's destruction of Area 51 plunged the world into a period of depression and war known as the Collapse. The Collapse shattered the global powers. It would be two decades before those with visions of a new world order would again vie for dominance."

- Deus Ex: Invisible War The Great Collapse is a major event that takes place between Deus Ex and its sequel Deus Ex: Invisible War.

When JC Denton destroys Area 51 during Deus Ex, the center of multimedia communication, and the Aquinas communication grid, the Internet is disabled and humanity descends into a period of war and economic recession known as The Collapse. It takes place over several months (indicated by J.C.) after the events of Deus Ex, and indirectly impacts almost every event in Deus Ex: Invisible War. Following The Collapse, transport between regions is slow as commercial air transportation is nonexistent and the only remote travel is facilitated through private pilots.

Explanations
"Twenty years ago, J.C. Denton shut down the Aquinas Router, which paralyzed global communication and returned civilization to a simpler, decentralized existence."

- Deus Ex: Invisible War In practical terms, Deus Ex ended with three possible endings. JC Denton could either choose to merge with an AI known as Helios, allow the Illuminati to regain control of the world by killing Bob Page and leaving the Area 51 intact, or destroy the Area 51 and the Aquinas system, removing the means by which any person or group could rule the world (with the side effect of destroying the world economy and creating a new "Dark Age").

The designers tried to incorporate all 3 endings into Deus Ex: Invisible War's plot. One of the possible solution of the end of Deus Ex is that when JC merged with Helios, the process created a power overload, which destroy Area 51 and killed Bob Page at the same time.

Introduction
While the specifics of the world collapse are not told (everyone in the game world has dealt with the events for more than two decades), it is implied that the sudden decentralization of communications and control caused long-dormant rivalries between nations to erupt into all-out war.

Among the mentioned singular events are the destruction of the Statue of liberty and UNATCO HQ, the event of nanite swells with subsequent use of nuclear weapons to put them down, an unknown incident which reduced Cairo international airport into a "landfill", and what seems to be the complete collapse of continental Russia which prompted the creation of the Omar as a survival meassure.

The Dentons go into hiding
For a while after the events of Deus Ex, JC Denton/Helios accomplishes much at his home base on Liberty Island. With the Statue of Liberty destroyed, JC's newfound knowledge of nanotechnology allows him to rebuild it as a brightly glowing spectre of its former self.

Regardless of what had been done, the strain on JC's body would eventually be too much for him, forcing him to go into suspended animation. A company known as ApostleCorp was started by Paul Denton in order to research an improved nanotechnology that would better allow JC to work with Helios.

This work would eventually lead to the creation of the Tarsus Academy, whose primary goal would be to test new generations of nanotechnology on "trainees". One of these would be Alex Denton, the main character of Invisible War.

The Illuminati Rebuild
Following the end of the Collapse, two major groups begin to form. The World Trade Organization (WTO) comes into power to rebuild society and its financial structure, and the Order Church forms as a means of support and care for those who have lost friends and family during the events of The Collapse.

Interestingly, while diametrically opposed to one another, the WTO and the Order are both secretly ruled by the few remaining members of the Illuminati: Chad Dumier, governor of the WTO, and his lover and Her Holiness of the Order Church, Nicolette DuClare.

This interesting arrangement — two groups violently opposing each other, yet ruled by the same people — was designed under the expert understanding of universe by the two Illuminati. Realizing that post-Collapse society would not tolerate a single governing body, they chose to split their attention. Those who would wish to see high profits and technology would flock to the WTO, whereas those seeking peace and spiritual fullness would join the Order.

Behind the Scenes

 * In an interview, Warren Spector said that he wanted to choose one of the three endings in Deus Ex to build Deus Ex: Invisible War upon, but later included elements of the other two. So while the Helios ending is present as the true canonical ending, elements from the New Dark Age ending are used (the merger eventually leads to the Collapse) as well as the Illuminati ending (following the Collapse, the Illuminati move in and take over). So while the player can choose not to merge with Helios at the end of the first game, the sequel is based upon that choice being made, and the repercussions of the other two endings as well.

Wielki Upadek