SYDNEY (AP) -- In the exploding hell of battle, a single hand poked through the earth.
John Cantwell could see the ridges and calluses of the skin, and the pile of desert sand that had swallowed the rest of the Iraqi soldier. The troops Cantwell was fighting alongside in the Gulf War had used bulldozing tanks to bury the man alive.
This hand -- so jarringly human amid the cold mechanics of bombs and anonymous enemies -- was about to wedge itself, the Australian man would write decades later, "like a splinter under the skin of my soul." It would lead, along with other battlefield horrors, to the splintering of his mind and to a locked psychiatric ward. And it would lead to the abrupt end of a 38-year military career that saw him ascend to remarkable heights as the commander of Australia's 1,500 troops in Afghanistan.
In the process, Maj. Gen. Cantwell would become two people: a competent warrior on the outside. A cowering wreck on the inside.
He hid his agony to survive, to protect his loved ones and -- he admits it -- to pursue professional glory. But in the end, the man with two selves found he had lost himself completely.
A disheartening number of veterans suffer post-traumatic stress disorder. What made Cantwell so extraordinary was his ability to hide his escalating pain for so long, while simultaneously soaring through the military's ranks -- eventually taking charge of an entire nation's troops in a war zone.
But the higher he climbed, the farther he fell into the abyss of mental illness.
"I became an excellent actor," he says, 20 years into his battle with PTSD and going public for the first time with the release of his autobiography, "Exit Wounds."
"It did, though, come at a price. It was like pressure building in a hose and you finally release the tap."
And when that tap was opened, Cantwell nearly drowned.
He had practically begged his way onto the battlefield.
In 1974, he joined Australia's Army as a 17-year-old private, after a childhood spent worshipping Vietnam veterans and poring over military-themed comic books. He ended up on exchange with the British Army, and two years later, the Gulf War erupted. Cantwell hounded his superiors for his first chance at combat. "Be careful what you wish for, John," one warned him. But on Dec. 17, 1990, he said goodbye to his wife and two sons and headed to the Persian Gulf.
It was exciting at first -- the strategizing, the explosions, the sense of being part of something big. He whooped with victory alongside his comrades when bombs blew apart Iraqi artillery.
Then came the hand.
Cantwell stared at it as his tank rolled past. He had been unnerved by the plan for American troops to bulldoze over a network of trenches hiding Iraqi soldiers, but had said nothing. Now he wondered: Had the soldier been reaching for help when he was entombed?
The U.S. Defense Department would later defend the operation as a necessity of war, arguing that the Iraqis who were killed had chosen to stay in the trenches and fight. The Defense Department's former spokesman, Pete Williams, told reporters at the time: "There is no nice way to kill somebody in war. War is hell."
On the battlefield, there was no time to process it. Cantwell was a warrior, and this was war. He pushed forward.
The horrors piled up. He saw the twisted, charred remains of men. He fought to stay calm when several small bombs exploded under his vehicle. Inside a blood-and-excrement-smeared torture chamber in a former Iraqi headquarters, he saw a drill, hammers, pliers and rope. He imagined the screams of the victims.
Through it all, he knew he must remain focused. That was what he had been trained to do, and he did. But there were moments when he felt something gnawing at him.
He was looking for survivors near a blown-out truck when he spotted the first head lying in the sand. A second head lay nearby, one eye staring back at him, a scarf still wrapped around the remains of the neck.
Cantwell felt an overwhelming compulsion to put the men back together.
With sweaty hands, he lifted the second head by the scarf and carried it over to its former body. He grabbed the other head by the hair and placed it alongside the shoulders to which it had once been attached.
Then he climbed into his tank, and got back to the business of war.