Until he was killed in 2006, Abu Musab al-Zarqawi, head of al Qaeda in Iraq, was implicated in the death of thousands. Back in 2003, he engineered the bombing of the United Nations Headquarters in Iraq that killed, among others, the UN Secretary-General’s special Iraqi envoy Sergio Vieira de Mello (immortalized by Pulitzer Prize-winning author Samantha Powers in her 2008 book Chasing the Flame: Sergio Vieira de Mello and the Fight to Save the World).

Zarqawi was likely responsible for the 2004 beheadings of American civilians Nicholas Berg and Olin Eugene Armstrong. Worst of all, also in 2004, he is considered to be the driving force behind the attacks on the Shia shrines in Karbala and Baghdad that killed at least 180 and kicked sectarian violence in Iraq into high gear.

We in the West tend to think nobody does terrorism like al Qaeda, as well as Middle-Easterners in general, such as the Taliban. But terrorism is not only an opportunistic infection, but an equal-opportuntunity one. In other words, the United States, too, has suffered outbreaks.

Setting the ravages of the CIA aside for the moment, we need only go back to the U.S. Civil War. In fact, let’s get a one-year jump on its 150th anniversary by dredging up its ugliest side and weigh how it stacks up against al-Qaeda.

For sheer cruelty, perhaps nothing in the Civil War matches the war between two states — Kansas and Missouri — in the War Between the States. Kicked off when John Brown attacked slave-holding Missouri, it reached a climax when the South’s William Quantrill led his guerillas in an attack on Lawrence, Kansas forgotten by many today. About 200 homes and businesses were destroyed and 150 killed, many shot up-close and personal.

Quantrill soon bowed out of the action (though he was later killed by Union troops). Carrying on, though, were some of his lieutenants, among them Bill Anderson, who gained notoriety for his raid on Centralia, Kansas and subsequent attack on the North Missouri Railroad, after which he ordered the execution of 24 Union soldiers. In Blag Flag: Guerilla Warfare on the Western Border, 1861-1865, Thomas Goodrich (Indiana University Press, 1995) describes the fate of another, larger Union force that surrendered to Anderson and his men. Think of Anderson like this: he trumped Quantrill in savagery as Zaraqawi did bin Laden and Zawahiri.

Goodrich quotes a surviving captive who Anderson was holding in hopes of exchanging for his men who were held prisoner by the Union.

“Surrendered, as we did at Centralia, with assurances of humane treatment. . . . No sooner was this accomplished than Hell was suddenly transferred to earth. . . . Men’s heads were severed from their lifeless bodies, exchanged . . . exchanged to bodies . . . stuck upon their carbine points, tied to their saddle bows, or sat grinning at each other from the tops of fence stakes and stumps around the scene.”

Nor were such atrocities enough to prevent Confederate General Sterling Price from enlisting Anderson and his men in the effort to drive Union forces from Missouri.

As we can see from incidents such as these, not to mention the, uh, cavalier way in which American forces have regarded the lives of Iraqi civilians, those we currently label terrorists have no monopoly on barbarism. Worse, when it comes to institutional, policy-driven savagery, considering that the forces it set in motion have resulted in the killing of as many as 1,500,000 Iraqis, the United States currently brooks no competition.