This visceral anti-Shia hatred was promoted by Zarqawi, who wanted to foment civil war in Iraq between the Sunni and Shia. He and his successors regard Shiites as "innovators" -- those who dare to interpret the Quran and therefore deny its perfection.
"The danger from the Shi'a ... is greater and their damage worse and more destructive to the (Islamic) nation than the Americans," Zarqawi once said.
ISIS sees Shia influence spreading in a crescent from Iran through Baghdad to Syria and the Shia militia Hezbollah in Lebanon. And it sees the United States as complicit in supporting a Shia government in Iraq.
Enslaving the disbelievers
Despite the enormous firepower, resources and technology that the U.S. and its allies can bring to the battlefield, ISIS is doing all it can to drag the West into a broader battle. Its gruesome murder of American hostages was part of this strategy of provocation; so were the attacks in Paris.
"They want us to become emotional," General Nagata said, according to the New York Times.
Embroiling the U.S. and the West in a land war -- ISIS reasons -- would give Muslims no choice but to come to the defense of the caliphate, setting up a global confrontation.
ISIS leader Abu Bakr al-Baghdadi specifically addressed the United States in the summer of 2014, when he said: "Soon we will face you, and we are waiting for this day."
"Now that it has taken Dabiq, the Islamic State awaits the arrival of an enemy army there, whose defeat will initiate the countdown to the apocalypse," wrote Graeme Wood in The Atlantic.
There can only be one victor in this struggle, according to ISIS' millenarian perspective. In September 2014, Adnani said the righteous "are always and forever victorious, since the battle of Noah and until Allah inherits the earth and those upon it."
And he added: "We will conquer your Rome, break your crosses, and enslave your women. If we do not reach that time, then our children and grandchildren will reach it."