While President Obama muddles an expanded war against the Islamic State in Syria and Iraq (ISIS), militants loyal to the caliphate just conducted the largest mass beheading to date—a thousand miles away, in Libya.

In possibly the most gruesome video yet, 21 Coptic Christians were beheaded by dagger-wielding masked militants of Ansar al-Sharia, a militant group that has pledged allegiance to the Islamic State. This latest video aims to send a powerful message to the “crusaders” (a term used to refer to Christians).

“Safety for you will be only wishes—especially when you are fighting us all together,” the video’s masked narrator says, speaking perfect English with an American accent. “Therefore, we will fight you all together until the war lays down its burdens.”

I watched the video so you don’t have to

The terrified men murdered for the propaganda video were among several Egyptian nationals who had crossed the border into Libya in search of work. They were abducted on Jan. 3 from the coastal city Sirte, near the center of the country, which is divided by two governments. Local witnesses told Al Jazeera that masked, armed men came in four vehicles with lists of names, specifically targeting Christians.

After a long, chilling silence, broken only by the sound of crashing waves, all 21 of the men are violently butchered by the figures who stand behind them brandishing identical knives and equipped with military-grade combat gear.

A man points his knife toward the sea and proclaims: “And we will conquer Rome, by Allah’s permission.” In a sinister tone, he continues: “And the sea you’ve hidden Sheikh Osama bin Laden’s body in we swear to Allah, we will mix it with your blood.” The video ends with a final crimson shot of precisely that.

Text from the video points to the conclusion that the mass killing was in revenge for a years-old dispute over the recapture of the wife of a Coptic priest who had converted to Islam and was forced by her husband to reconvert to Christianity upon returning to Egypt.

Who were the hostages?

The Copts, a sect of Christianity native to Egypt and making up about 10 percent of the population, have faced intense discrimination especially in the years since Egypt’s revolution. Following its support for the 2013 coup that ousted President Mohammad Morsi, members of the deposed Muslim Brotherhood—once the dominant political power, now labeled a “terrorist group” by current President Abdel Fattah al-Sisi—targeted the Coptic Church and its adherents.

Egypt’s Foreign Affairs Minister Sameh Shoukry previously stated the army would stay out of the neighboring country’s deteriorating conflict, focusing instead on sealing its borders and cracking down on “domestic forces of extremism.” This time, however, Egypt launched airstrikes in coordination with Libyan air forces against Sirte and Tripoli, killing 50 Islamic State militants “to avenge the bloodshed and to seek retribution from the killers.”

The mess is getting worse

Things have really gone to hell in Libya since Muammar Qaddafi died at the hands of rebel forces in 2011. Last month, armed rebels loyal to the Islamic State beheaded two Tunisian journalists and rammed a car bomb into the gates of a luxury hotel in the capital. After the men stormed in with grenades and Kalashnikovs, and detonated explosive belts inside, a commander of security forces said the pandemonium was “under control.”

Things are definitely not under control. Libya is arguably in a state of total anarchy. The standing government in Tripoli was declared illegitimate by the supreme court late last year, and an entirely separate government set up shop, claiming to the “official” government of the country. The United Nations doesn’t know what to do, but still recognizes the government-in-exile in Tubruq, on the other side of the country, while it tries to broker a deal between the two competing regimes.

Correction: Hannibal assembled his troops against Rome in Iberia (now a large portion of Spain).

Illustration by Jason Reed