It's the year 2021 and the streets of every single major city of the United States are filled with millions of angry protesters. The protests are so massive, and involve so many people that it's impeding the functioning of transportation, businesses and infrastructure in general. The U.S. economy is losing billions of dollars every day, and the entire U.S. political system is in danger. The protests are mostly (physically) non-violent. Yet they cause a massive disruption in the functioning of society. Roads are closed. Many businesses are unable to function. Much of the civil activity in the US is now based around providing for and assisting the protestors materially and logistically.
The reason for the protests is that the protesters have some very specific beliefs, which I'll soon list. Though very similar to ours, this is an alternate universe, so whether the beliefs are actually true or not in this alternate universe is not given. Your goal, however, is the same regardless. We'll get to what your goal is.
Here's what the protestors believe:
- Elements of the U.S. government (and possibly other governments) were involved in the September 11, 2001 attacks.
- The destruction of the Twin Towers and Building 7 was assisted by some prearranged technology.
- The Pentagon was not impacted by a commercial airliner on September 11. Rather, the damage seen there was caused by something else.
- No commercial airliner crashed in Shanksville, Pennsylvania on September 11.
Credible polls show that more than 80% of the U.S. population at large believes these things. 15% say they have doubts. Only 5% say they believe the narrative that was initially presented. Naturally, these beliefs lead to many other associated beliefs as well.
Now, this is an alternate universe, but unless otherwise stated (like I did above), it is the same as our own.
In this alternate universe, you can decide what the President, Congress, Senate, Supreme Court and other US government bodies shall do. Congressmen, Senators, etc, will follow your course of action perfectly. This also applies to the management and key individuals of government agencies such as NIST, FEMA, etc. It also applies to the top brass of the armed forces, and top police, FBI, CIA, etc. However, the minds of the regular employees in these agencies are like normal citizens, totally beyond your control. You can only control them the way the top officials could in our real world, through orders etc.
Your aim is to restore the normal functioning of infrastructure, the economy, the government, etc. Basically, you want people to go back to their homes and continue their normal lives.
No new evidence or data (photos, videos, classified documents, including the 28 pages) have been released regarding 9/11 since now (April 2016). Moreover, the evidence (videos, photos, recorded eyewitness statements, physical evidence, etc) pertaining to the events is exactly the same as in our universe. You can not produce new evidence, or magically remove things, but you can declassify things if you think there is reason to believe that the US Government has it.
Now. Whether, in your universe, the protesters' beliefs are accurate or not: How do you deal with them, and restore the normal functioning of society, the economy and the government?
Some knowledge about details from the real world relevant to the beliefs of protesters may be useful for answerers to know.
It doesn't matter how many drastic things have to happen for you to achieve your goal. As long as you end up with a functioning society with working infrastructure, government, industries, etc, you have answered the question. There can be as many drastic changes and events in the process that you want.
Edit 2: Goals of protestors:
Since 80% of the US population is aligned with the protestors, they are an extremely diverse group. The only thing they have in common are the core beliefs described above. There are thousands of factions who believe different things about the other details, and what should be done. In spite of these differences, the protestors are largely united. However here are some things most of them believe should be done:
A new investigation into the September 11 attacks with subpoena power and full access to absolutely all classified documents and data. They also want the public itself to have direct access to all that information
They have a long list (there are actually many, differing, such lists) of people they believe were involved in 9/11 (including covering up the crimes in the aftermath). They believe those people should be prosecuted for treason.
Other than that, the beliefs and demands of the protestors are so diverse that it's impossible to make any adequate summary.