Insurgents are stealthy fighters, their attacks unexpected, startling and violent.

Combined with the stress of longer deployments, loneliness and brutal desert conditions, they are the perfect trigger for Post-Traumatic Stress Disorder.

Soldiers now returning from Iraq and Afghanistan are experiencing the highest levels of PTSD since the Vietnam War.

Some just have trouble sleeping. Some find themselves emotionally numb or easily startled.

In the most extreme cases, soldiers have killed themselves – and fellow soldiers.

The nonprofit aid organization Veterans for Common Sense said that as of December 15, 2008, the U.S. Department of Veterans Affairs, or VA, had diagnosed 115,000 Iraq and Afghanistan vets with PTSD.

“These are staggering numbers,” said VCS executive director Paul Sullivan. “We can either admit that there’s a very serious problem and begin treatment, or we can ignore the problem and wait until the PTSD turns into unemployment, drug use, and suicide – very expensive social problems.”

The National Institute of Mental Health defines PTSD as “an anxiety disorder that can develop after exposure to a terrifying event or ordeal in which grave physical harm occurred or was threatened,” and says military combat could be a trigger.

Tom Tarantino, legislative associate for Iraq and Afghanistan Veterans of America, the largest group dedicated to veterans of conflict in the Middle East, estimated that as many as one in four returning servicemen had diagnosable PTSD.

“No one comes back from war unchanged – as many as one-third come back with some kind of PTSD, depression or traumatic brain injury,” he said.

According to IAVA, the country’s largest organization dedicated to the welfare of recent veterans, there is a total of 1.8 million alums of the fighting in Iraq and Afghanistan.

Due to dwindling enlistment and troop surges, many served more than one tour of duty in the Middle East.

“There’s a very severe soldier shortage,” Sullivan said. “Soldiers deployed twice or more to the war zone have a 50 percent increase in the risk of returning home from combat with PTSD, compared with those who went just once.”

The military defends its mental health assessments and policies.

“No military in the history of the world has done more to identify, evaluate, prevent and treat the mental health needs and concerns of its personnel than the Military Services of the United States,” said Pentagon spokeswoman Eileen Lainez.

But Sullivan disagrees. A Gulf War veteran, he says the very nature of combat in the Middle East – no set battles, but thousands of unexpected assaults at checkpoints, bases and roads by stealthy insurgents -- is the perfect breeding ground for PTSD.

“They call it ‘360/365,’” he said of the stress that comes with not knowing when the next battle will come. “They’re completely surrounded -- 360 degrees, 365 days of the year. Everyone thinks war is just you fight, then go back to the clubhouse and play video games and eat pizza.”

The military currently provides mental health support in combat theaters to respond to the mental health needs of service members in the field in Iraq and Afghanistan.

Within five days of returning home from a tour of duty, soldiers complete a Post Deployment Health Assessment and have a one-on-one review with healthcare professionals in which they discuss any health concerns, though these sessions are not tailored to mental ailments.

Three to six months after returning home, they are asked to complete the Post Deployment Health Re-Assessment, which does a follow-up check on any mental or physical health concerns.

“The DOD is actually doing a fairly decent job compared to how it used to be done. They’ve finally gotten the message,” Tarantino said. “We need to train our junior leaders to identify mental health injuries – and they are injuries. They are as a result of trauma, so it’s just like getting shot or getting blown up. We need to train our sergeants, our lieutenants, our captains and our colonels.”

Meanwhile, debate has been raging between the military and veterans’ groups who say soldiers with diagnosed PTSD are being forced to return to duty due to troop shortages.

“It’s a very serious problem,” Sullivan said. “The military had already deployed thousands who shouldn’t have been.” He referenced an “entire planeload of soldiers from Ft. Carson who were unfit,” but still taken back to war.

“One was taken out of a mental hospital, and another committed suicide in the war zone,” Sullivan said.

Some soldiers, affected by mental health stigma and a can-do attitude, may also try and hide their problems from military bosses.

“Servicemen and women aren’t being properly screened,” Tarantino said. “The stigma of mental health is so big within the military that a lot of service members just have that ‘suck it up’ mentality. These are people who do a lot of extraordinary things at an extremely young age with very little resources.”

He also noted a lack of support for veterans of the National Guard.

“Their situation is much more dire,” Tarantino said.

“They can go from Baghdad to their front door in 36 hours and they don’t have access to the resources and community that the army does.”