Nearly half a million people have perished in the seemingly never-ending mayhem in both Iraq and Syria. Both the Iraqi and Syrian peoples have witnessed widespread and systematic torture, rampaging death squads, devastating suicide bombings, indiscriminate shellings and bombings, and even the horrors of chemical warfare. Yet just when I thought little more could truly shock me, ISIS begged to differ.

James Foley, Steven Sotloff, David Haines, and now Abdul-Rahman Kassig. Each of these men dedicated their lives to serving the long-suffering Syrian people, either by sharing with the world their stories and exposing the truth as journalists, or to alleviate their suffering as aid workers. They all were ready to risk their personal safety and well-being, and ultimately lost their lives to a group so mindlessly bloodthirsty that even Al Qaeda was forced to reject this particular brand of evil.

The Reign of Terror Effect

The rise of groups like ISIS follows a historic pattern which has been a tragic part of the aftermath of many violent revolutions, from the iconic 1789 French Revolution to the 1979 Iranian Revolution. Masses of idealistic reformers -- especially the youth -- who initially rise up against the regime are systematically and brutally subjugated. Years of state oppression and outright state terrorism eventually breeds new groups of hardened combatants willing to take any means necessary to secure "victory," including the rampant abuse and subjugation of the very people they purport to fight for. Upon securing power -- either in part or in full -- these groups subsequently rule with a brutality which rivals the very regime they fought to overthrow.

In the case of Syria and Iraq, ISIS' genesis is borne of men who had been tortured in both Syrian and Iraqi prisons for years. Their ranks are further dominated by legions of foreign forces who have no connection with the local people. All of this has led to ISIS attacking nationalist Syrian revolutionaries and Sunni Iraqis who oppose their rule just as consistently and brutally as they have their staggering number of enemies (both the Iraqi and Syrian governments, the Kurds, religious minorities, neighboring and regional countries, and the broader international community).

The Logic of Political Gangsterism

I have often been asked why ISIS beheads its victims. My response? The same reason Mexican drug cartels have been doing so for nearly a decade: it's a total gangster-power move. Their goal is to brutalize and humiliate their victims, and to intimidate and terrorize their purported enemies. The cold-blooded murder of Abdul-Rahman Kassig absolutely encapsulates the nihilistic cynicism of ISIS and their supporters. After Kassig completed his military service in Iraq, he founded the medical relief group Special Emergency Response and Assistance and dedicated the remainder of his life to humanitarianism. He even embraced Islam and changed his name from Peter to Abdul Rahman, thereby joining a 1.6 billion strong family of global believers.

Ultimately, none of this would save his life. ISIS' murderous campaign against journalists, human rights activists, and aid workers -- local and foreign; men and women -- has long been as ruthless as it has been indiscriminate. Countless courageous and selfless people in both Syria and Iraq have fallen victim to their tyranny, just as they have to both Assad's regime and the chaos of post-invasion Iraq. For a legion of degenerates who have no qualms blowing up entire mosques full of worshippers , killing one more humanitarian and Muslim meant nothing. Indeed the fact that Kassig was an American Muslim almost certainly gave this cult of death an even more perverted satisfaction for killing a "traitor." Within the twisted and perverse "logic" of this group of neo-kharijites, such killings are simply business as usual.

My Brother in Faith and Humanity

Yet I still desperately hoped that Abdul Rahman's faith just might save him from the fate of so many of his predecessors. The news of his murder shook me to the core, and simultaneously filled me with sorrow, anger, horror, disgust, shame, and a combination of a half-dozen other emotions which cannot be properly expressed through words alone. Abdul Rahman Kassig was my brother in both faith and humanity, and had a greater passion for humanitarianism and death-defying courage than I ever have.

One of Kassig's Syrian colleagues perhaps best encapsulates my own reaction and that of the collective global community of Muslims:

Burhan Agha, a Syrian who worked with Kassig in Lebanon, wept when recounting his friend's humanitarian work. "If I could apologize to each American, one by one, I would, because Peter died in Syria, while he was helping the Syrian people," Agha told The Associated Press by telephone from Switzerland, where he is seeking asylum. "Those who killed him claimed to have done it in the name of Islam. I am a Muslim and am from Syria. ... (His killers) are not Muslims."

The response from his grief-stricken yet proud parents is as agonizingly heartbreaking as it is inspiring:

Ed and Paula Kassig of Indianapolis said in a statement that their 26-year-old son, Peter Kassig, "lost his life as a result of his love for the Syrian people and his desire to ease their suffering." "We will work every day to keep his legacy alive as best we can," they said.

As increasing numbers of journalists and aid workers risk their lives and even make the ultimate sacrifice to try and make our world a better place, we should do everything we can to make their mission easier. In honoring their memory, we should do everything we can to ensure that their courageous sacrifice was not in vain.

Anything less is a disservice to the very people they dedicated their lives to help, and represents a collective failure of humanity.

Inna lillahi wa inna ilayhi raji'un -- May God have mercy on your soul.

Dedicated to the family and loved ones of James Foley, Steven Sotloff, David Haines, and Abdul-Rahman Kassig, and all thoughts and prayers are with the remaining aid worker being held by ISIS.