He displayed his art at the Los Angeles gallery a month after the Sept. 11 terrorist attacks, the start of an era of thus-far ceaseless war. He remembers the reaction. “People were like, ‘Oh my God, your work is so timely,’” he said. “I was talking about the Gulf War in 1991. But O.K., it will be about the next war, too, which unfortunately has come to pass.”

That was almost two decades ago, as the American attack on Afghanistan was beginning, before the invasion of Iraq and the expansion of the so-called Global War on Terror across more of the map. “The whole time I have been making cups the wars have been going on,” Tool said. “And it’s just crushingly depressing.” In sorrow, Tool cemented his mission. As he made more war-related cups, pottery became his life.

He left the Marine Corps as a sergeant in 1994 and graduated from the University of Southern California with a Bachelor of Fine Arts in 2000. After his exhibition in 2001, he relocated to the University of California, Berkeley, where in 2005 he received a Master of Fine Arts and was hired as the senior studio technician for ceramics in the Department of Art Practice. Now 48, Tool still holds that job, which provides him his income. In his spare time he sits before a pottery wheel in the basement studio of the off-campus home he shares with his family, making more cups.

It is a dark output. On Tool’s work, people are manipulated, misused, abused and suffer and die. The scale is vast and the images usually disturbing. Knockoffs of Sailor Jerry’s classic military tattoos float above stacked skulls. Captain America stands astride sandbags and bones. Predator drones alternate beside panels of traditionally dressed Afghan men. A soldier snarls out a single word as a warplane trailing a plume of poison mist passes overhead: “Spray!”

Pornography is presented alongside the American flag. The tools of killing — hand grenades, cluster bombs, modern rifles and cartridges, attack gunships, knives, swords, arrows and more — are assigned repeated cameos, as are military insignia and medals, including the American military’s civically sanctified Purple Heart, issued for combat deaths and wounds.