Charles Williams had planned to become a ROTC teacher after he left the military, but was wounded by an RPG attack in Afghanistan.

NEW YORK (CNNMoney) -- After more than a decade of continuous warfare, the cost of disability compensation for wounded veterans is surging to mammoth proportions.

The U.S. Department of Veterans Affairs expects to spend $57 billion on disability benefits next year. That's up 25% from $46 billion this year, and nearly quadruple the $15 billion spent in 2000, before the wars in Iraq and Afghanistan began.









"This is the cost of going to war," said Larry Korb, a senior fellow at the Center for American Progress who served as assistant secretary of defense during the Ronald Reagan administration. "We've made so much progress in medicine [that] you're going to have a lot of people survive their injuries who didn't in the past."

About 4,500 U.S. troops were killed in Iraq and about 1,800 have been killed in Afghanistan. Some 633,000 veterans -- one out of every four of the 2.3 million who served in Iraq and Afghanistan -- have a service-connected disability, according to the Bureau of Labor Statistics.

The VA designates some of these veterans as partially disabled, while others are considered fully disabled, depending on the extent of their injuries. The classifications determine how much money they're paid in benefits, but it doesn't prevent disabled vets from earning their own money, if they're capable of doing so.

The VA granted full disability to Sgt. Sean Long of the Georgia National Guard, who survived grisly wounds in Iraq in 2005 when "friendly fire" punched two .50 caliber bullets through his left leg.

Long said the rounds "peeled me back ... like a banana" as they broke his knee cap and femur and severed his femoral artery. He was evacuated by helicopter to a hospital in Iraq, then Germany, and eventually Walter Reed National Military Medical Center in Bethesda, Md.

"I was in the hospital for three months," said Long. "I stopped counting at 35 operations in 45 days. I had over 50 pints of blood put in me."

Now he's on 100% disability. The compensation rate for full disability is $2,769 per month for a veteran with no dependents, according to David Autry, a Navy veteran and spokesman for the advocacy group Disabled American Veterans. Vets with families generally receive larger benefits, and those that have lost of a limb or reproductive organ are also eligible for additional compensation, ranging anywhere from $99 to $8,000 per month.

Long sometimes works in construction, even though he can't bend his leg, suffers "extreme pain" while walking on loose terrain and often uses a cane. Long, who has a 13-year-old daughter, might not have survived these injuries in an earlier war without medevac and modern medicine.

"Equipment providing personal protection from many serious injuries as well as the speed and quality of medical attention have been major factors in saving lives," wrote Marine veteran James Wright, former president of Dartmouth College and author of "Those Who Have Borne the Battle."

In his book, Wright looks at how the odds of surviving battle wounds have changed over the last 250 or so years. During the Revolutionary War there were 1.4 "nonmortal" wounded for every soldier killed in combat. That ratio rose to 2.3 in World War II and 2.6 in Vietnam. The ratio more than tripled in Iraq and Afghanistan, where there are more than seven wounded survivors for every soldier killed.

The predominant use of improvised explosive devices, or IEDs, and rocket-propelled grenades, known as RPGs, in Iraq and Afghanistan has caused an epidemic of amputations and brain injuries. Modern medicine is keeping these soldiers alive, but such catastrophic wounds are difficult and expensive to treat. Many soldiers also become psychologically disabled from post traumatic stress disorder, or PTSD.

Army Sgt. 1st Class Charles Williams suffers from multiple combat injuries. His platoon was ambushed in Afghanistan by Taliban fighters in 2006. An RPG struck and detonated a nearby ammunition box full of Mark 19 grenades, spraying him with shrapnel and throwing him 30 feet into a wall.

Williams said he completed his tour, but was medically retired in 2011 with 100% disability compensation for a brain and shoulder injury, as well as PTSD. While he still has all his limbs, he said that he's incapable of working even a desk job, because of hemiplegic migraines that temporarily paralyze the right side of his body and eliminate his ability to speak.

"Some days, you can look at me and you wouldn't tell there was anything wrong with me," he said. "And then other days, my hands are shaking so bad I look like I have Parkinson's and I can't hardly feed myself."

In addition to Williams' disability compensation, the VA pays his wife, Giovanna, $1,200 monthly to serve as her husband's caretaker. Despite these payments, the couple says they're struggling financially, ever since their house in Leesville, La., was wrecked by a flood in March.

"I'm not looking for no handouts and nothing like that," said Williams, who prior to his injury had been planning to get a job with a high school ROTC program. "A lot of this is kind of embarrassing to me because I can't go to work."

Autry of Disabled American Veterans said the difficult economy has pressured some vets into seeking benefits when they otherwise wouldn't.

"It seems like in periods of economic stress, vets will turn to the VA for health care and other benefits in larger numbers, just like they turn to the military during rough economic times," he said.

Many of these veterans are young people in their 20s who go on full disability for the rest of their lives, putting a huge strain on the VA. Robert Gates, former Defense Secretary, addressed this in 2010.

"Gates, right before he left, said health care costs are eating us alive," said Korb, a Navy veteran. "I think that's a critical thing."