A Save a Warrior class for veterans in California forms a support circle.

Editor’s Note: Carol Costello anchors the 9 a.m. to 11 a.m. ET edition of CNN’s “Newsroom” each weekday. The opinions expressed in this commentary are solely those of the author.

Story highlights

Carol Costello: The prospect of having to send combat troops to fight ISIS is sobering

She says if they're needed, we should prepare for new wave of veterans with PTSD

The impact of having to kill or be killed can be deeply wounding psychologically, she says

Costello: If the mission is fuzzy and timetable indefinite, the risks increase

CNN  — 

Joint Chiefs Chair Martin Dempsey made no bones about it. If he believes U.S. troops advising the Iraqis in the fight against ISIS should aid them in a combat role, he will seek permission from the President.

President Obama and most lawmakers say American “boots on the ground” will not happen, but you know how that goes. As Sen. Lindsey Graham said of ISIS in Syria: “It’s going to take an army to beat an army. This idea we’ll never have any boots on the ground to defeat them in Syria is fantasy.”

So, I, like many American civilians, worry. Our troops are amazingly skilled and courageous in theater, but a stunning number of them do not fare well – psychologically – once they come home.

To my mind, we don’t realize there are lasting effects of war we cannot see. Let’s face it, after the touching reunions we witness and the obligatory applause we give when we see a soldier in uniform on a plane, we go on with our lives. As Lt. Col. Rick Francona, a CNN military analyst, told me, “The biggest fear for those of us who serve is: We’ll be forgotten.”

The United States appears to have one of the highest rate of veterans/soldiers suffering from post-traumatic stress syndrome in the world. According to the General Health Questionnaire, U.S. soldiers experience PTSD at rates of 21-29%, compared to Britain, for example, where 16-20% of soldiers report signs of typical mental disorders, roughly the same as in the general population.

Carol Costello

What’s more troubling is the suicide rate. Twenty-two veterans commit suicide every day. That’s a suicide every 65 minutes. That’s 8,000 veterans a year.

Dr. Joel Dvoskin, a clinical psychologist, says, “William Tecumseh Sherman said, ‘War is hell.’ As far back as there have been wars, there have been people who didn’t handle war well. I suspect it’s a minority of people who do.”

Think about it. The military takes normal people and trains them to do, without question, the most un-natural thing in the world – to run toward danger, not away from it. To justifiably kill without question.

“Most people are affected significantly by killing, but not all in the same way,” Dvoskin told me. “For most people it’s not a joyful experience, for some it’s mildly traumatizing and for some it’s extremely traumatic.” The problem is, adds Dvoskin, there is no way to predict who is best equipped to deal with violent death.

Lt. Col. Francona, a veteran of both the Vietnam and Iraq wars witnessed death up close and personal and came close to dying himself.

“There’s not a day that goes by that I don’t think about it. I see it right now.”

The year was 1995. October 30. It was 3:14 in the afternoon. Francona was in northern Iraq on a mission for the CIA. He and his fellow team members were trying to broker a ceasefire between warring Kurdish factions so they could overthrow Saddam Hussein.

“I was writing a report on a laptop – an IBM Thinkpad – and the next thing I knew, I was thrown to the floor.” He shouted, “What was that?’ But he could not hear himself. The blast had temporarily deafened him. Francona crawled through the dust, the paper, and the debris to grab a weapon. “I was NOT going to be a prisoner,” he told me.

As he stumbled outside to help his fellow soldiers the images that haunt him today did not fully hit him. For a time, he was all business.

“There was a lot of smoke. A lot of people screaming. Lots of pieces. Hands. Feet. Torsos.” At this point Lt. Col. Francona – a tough guy in my book – started to cry. “They were just people. Defenseless people. I didn’t know who was dead. I didn’t want to know. I wanted to survive.”

Francona then told me, “I don’t talk about this. I don’t like to talk about it.”

Col. Francona would gladly serve his country again, but it’s clear the effects of real-life violence will be with him the rest of his life.

Terry Lyle, a psychologist who treats combat stress, actually thinks the suicide rate among soldiers may be higher than the statistics show. He and other experts I talked with are conflicted about why. “We do live in a violent society,” they say. “Americans are tough. We’re cowboys.” Yet, a vast of number of veterans never recover from what they witness on the battlefield.

Some experts wonder if it’s a “generational” issue. World War II veterans, for example, while often traumatized, seemed better equipped to deal with what they saw on the battlefield.

“World War II vets were mentally tougher because, growing up, they lived a tougher life,” Lyle told me. After all, World War II vets grew up during the Great Depression. “They just grew up with fewer creature comforts and frankly, they just sucked it up and dealt with it.”

Those vets did “deal with it”… silently. A Cleveland Plain Dealer story points to a 2008-2009 University of Michigan study. It looked at 78 veterans above the age of 60 and found 38% of them had “significant PTSD symptoms.”

The article also points out, World War II veterans come from a generation “in which expressing psychological symptoms or distress was pretty stigmatized. So these cases may have gone untreated as the vets did not seek treatment and were able to somehow suppress their symptoms and function.”

Others, like Lt. Col. Todd Yosick, told me serving in World War II and Iraq is “apples and oranges.” Yosick, who served in Iraq and is a social worker in the U.S. Army, told me, “The difference is turning it on and turning it off.” World War II vets were able to come home and stay home for good. Veterans nowadays return to the battlefield for multiple engagements. The constant adjusting to war, then home, then war can play with your mind and – these are my words, not Col. Yosick’s – can stress a soldier to the breaking point.

Veterans of World War II also had a mission they clearly understood and passionately believed in. “If the mission is foggy, then it makes it much more difficult for a (soldier) to justify killing,” Lyle told me. The secret to surviving war is if you “can justify the motive for (killing).” If you can, “it is heroic, not terroristic.”

That’s why so many Vietnam vets suffered from psychological problems. (The average age of male veterans who commit suicide is in the late 50s.) If you don’t know what you’re fighting for, it’s difficult to justify taking a life.

Sadly, if American troops do head back to the battlefield they will still grapple with a mission that’s foggy and a war with no discernible end.

So, I worry. Not that our brave men and women won’t ably serve to protect me, but that they’ll suffer for it and there is little, I, or anyone else can do that can truly compensate for that.

Read CNNOpinion’s new Flipboard magazine.

Follow us on Twitter @CNNOpinion.

Join us on Facebook.com/CNNOpinion.