
The "action" of 9/11 resulted in the "reaction" of Sam Harris starting to pen, the day after 9/11, his religion-denouncing book The End of Faith (2004), which worked to seed "new atheism" movement, led by Richard Dawkins (2006) and Christopher Hitchens (2007), in the years to follow. [1]

The "action" of 9/11 resulted in the "reaction" of Sam Harris starting to pen, the day after 9/11,
his religion-denouncing book The End of Faith (2004), which worked to seed "new atheism" movement, led by Richard Dawkins (2006) and Christopher Hitchens (2007), in the years to follow. [1]

In atheism, new atheism refers to a non-closeted type of atheism, initiated in the wake of 9/11, generally defined as an "atheist who is finally speaking up" (Dave Rubin, 2015), as defined amid erudite discussion (V:38:00-39:00) with Sarah Haider.

Overview
The term “new atheism”, is not new, and has been used nearly every decade, according to Google Books, going back at least the last two centuries; to cite one example:

“And in fact there are atheists. Atheism, both theoretical and practical, is a profound vice, — or rather, the radical vice of the heart and human mind. No age has been free from it. Our own is more fully infected by it than we think. Practical atheism is visible to every eye, and philosophical atheism is revealed under the form of pantheism. More yet, express, exact, avowed, and declared atheism has a school of its own; and this school of new atheism, more scientific than the old atheism, is built upon a foundation which it calls Modern Science.”
— Auguste Gratry (1892), Guide to the Knowledge of God (pg. 16)

In 1986, Christian apologeticist Robert Morey published The New Atheism and the Erosion of Freedom, written in the wake of the atheism wave of George Smith (The Case Against: The Case Against God, 1979), whom he debated on a radio show, and Madalyn O’Hair, the 1960 champion of school prayer abolishment.

On 1 Nov 2006, Gary Wolf penned his Wired article “The Church of the Non-Believers” (Ѻ); which opens to the following:

“It`s a question you may prefer not to be asked. But I`m afraid I have no choice. We find ourselves, this very autumn, three and a half centuries after the intellectual martyrdom of Galileo, caught up in a struggle of ultimate importance, when each one of us must make a commitment. It is time to declare our position. This is the challenge posed by the New Atheists. We are called upon, we lax agnostics, we noncommittal nonbelievers, we vague deists who would be embarrassed to defend antique absurdities like the Virgin Birth or the notion that Mary rose into heaven without dying, or any other blatant myth; we are called out, we fence-sitters, and told to help exorcise this debilitating curse: the curse of faith.”

This was followed by Simon Hooper’s 9 Nov 2006 CNN article “The rise of the ‘New Atheists’”. (Ѻ) After this point, an atheist "trinity" of Richard Dawkins (The God Delusion, 2006), Sam Harris (The End of Faith, 2004) and Daniel Dennett were being billed as the "new atheists" in a significant manner. [3]

In 2007, Christopher Hitchens published his God is Not Great, and the "atheist trinity" turned into the "four horseman" of new atheism.

In 2007, Peter Joseph’s uploaded his viral documentary Zeitgeist, on the Osiris-Horus Jesus connection, which worked to weaken the legs of theism, from a religio-mythology scholar approach.

Harris | Ideology
The following gives an example of new atheism logic:

“Only 28 percent of Americans believe in evolution; 72 percent believe in angels. Ignorance in this degree, concentrated in both the head and the belly of a lumbering superpower, is now a problem for the entire world.”
— Sam Harris (2005), postscript “Afterword” to The End of Faith

“No one is suffering under the doctrine of Islam more than Muslims are—particularly Muslim woman. Those who object to any attack upon the religion of Islam as ‘racist’ or as a symptom of ‘Islamophobia’ display a nauseating insensitivity to the subjugation of women throughout the Muslim world. At this moment, millions of women and girls have been abandoned to illiteracy, forced marriage, and lives of slavery and abuse under the guise of ‘multiculturalism’ and ‘religious sensitivity.’ This is a crime to which every apologeticist for Islam is now an accomplice.”
— Sam Harris (date) (Ѻ)

A Harris new atheism favorite is the morality of "throwing acid in the Islam girl" immorality example. The recent story of the building of Islamic schoolgirls who were left to burn to death because the fireman wouldn’t go into the building because the girls weren’t wearing Burkas, is one example a new atheist might employ for a call for faith reformation.

Quotes
The following are related quotes:

“After Harris came high pope Dawkins, then cardinal Hitchens, the bishop Dennett, and then the lower and more moderate figures in this new atheist priesthood: Krauss, Stenger, Atkins, Shermer [and all the rest] e bella compagnia.”
— Bo Jinn (2013), Illogical Atheism (loc. 286)

“Kierkegaard’s central concern was faith and the problems of faith. Today, the evolutionary biologist and sometimes children's author Richard Dawkins is at the forefront of the faith debate. The philosopher and cognitive scientist Daniel Dennett is a frequent contributor, as well as the neuroscientist Sam Harris. The late, great Christopher Hitchens was the angriest and funniest participant. We'll call these figures the new atheists.”
— Morgan Meis (2013), “The First New Atheist” [2]

See also
● Atheism timeline
● Four horsemen of atheism

References
1. Harris, Sam. (2004). The End of Faith: Religion, Terror, and the Future of Reason. W.W. Norton & Co.
2. Meis, Morgan. (2013). “The First New Atheist”, The Smart Set, May 8.
3. Thims, Libb. (2017). “Who coined the term New Atheism?” (Ѻ), Quora, Jul 27.

Further reading
● Haught, John F. (2008). God and the New Atheism: a Critical Response to Dawkins, Harris, and Hitchens. Westminster John Knox Press.
● Stenger, Victor J. (2009). The New Atheism: Taking a Stand for Science and Reason. Prometheus Books.

External links
● New atheism – Wikipedia.