You can see McMaster say this beginning at the four-minute mark:
“We are engaged today, as General George C. Marshall’s generation was engaged, against enemies who pose a great threat to all civilized peoples. As our World War II generation defeated Nazi Fascism and Japanese imperialism, and as later generations defeated Communist totalitarianism, we will defeat today’s enemies, including terrorist organizations like Daesh, who cynically use a perverted interpretation of religion to incite hatred and justify horrific cruelty against innocents.” — Lt. Gen. H. R. McMaster, speech to Virginia Military Institute, Center for Leadership and Excellence, November 21, 2016
In this video also, from May 2016, McMaster says this same thing. At 14:43, McMaster refers to “groups like ISIL, who use this irreligious ideology, this perverted interpretation of religion to justify violence. They depend on ignorance, and the ability to recruit vulnerable segments of populations to foment hatred, and then use that hatred to justify violence against innocents.”
This could be Barack Obama or John Kerry speaking.
As I explained here, this was during the Obama regime, when that was the official policy of the U.S. government, but President Trump has repeatedly criticized his predecessor (and his 2016 election opponent) for not being willing to call the problem of jihad terror by its right name. Since he has become President, he has repeatedly reiterated his determination to eradicate “radical Islamic terrorism.” If McMaster genuinely holds the view that the Islamic State is not Islamic, then he is a disastrous pick as National Security Adviser, and will continue the willful ignorance of the Obama administration, hamstringing efforts to understand, and counter effectively, the motives and goals of the enemy.