Did you even read your article from
Christianity Today?
"Which of these stages is meant to be normative for Islam?
According to standard Islamic jurisprudence, it is the fourth—expansionist jihad, understood as armed struggle against unbelievers, whether or not the Muslim community has been attacked. The law of abrogation in Qur’anic hermeneutics (see Suras 2:106; 13:39; 16:103), in which later revelation always trumps earlier texts, affirms this.
Islamic history bears out this expansionist bent. One century after the appointment of the first caliph, Abu Bakr, Islam had become an empire reaching across North Africa up to Spain in the west and across Asia into India in the east. By the end of the next century (the second century Anno Hegirae), Muslim territorial conquests had peaked, and Islamic jurisprudence had fully defined the behaviors and conditions governing “holy war.”
The terms of jihad closely parallel Augustine’s “just war” conditions. Only proper government authorities can conduct jihad. Fighting must avoid harming non-combatants, hostages, prisoners, and property (especially trees and landscape), and its ultimate goal must be to secure justice and peace.
For Islam, however, the causes of justice and peace are synonymous with the advance of the Muslim state, for politics and spirituality are inextricably bound together in the dream of one world under the complete dominion of Allah and His followers. So whereas Christian “just war” principles do not support the notion of establishing the kingdom of God by force, the Islamic doctrine of jihad unapologetically does.
When the ummah (community or state) of Islam faces its history of coercion and expansion, there is no shame or repentance. Islam, unlike Christianity, teaches in its most authoritative sources that force is justifiable in the cause of Allah. Far from feeling regret over past conquests, Islam takes pride in this heritage.
Indeed, many Muslims look back on the first three centuries of Islam as the golden years of their heritage and long for a return to world ascendancy."
They take pride in it; but you think it’s ancillary. They’ve practiced it through history to expand the Islamic state; for you it’s a mere appendage!