My name is Jack, and I'm a combat veteran. ("Hi, Jack!")

Please note that being a combat vet doesn't make me more eligible than you or anyone else to run for office. It doesn't even qualify me to advise you on whom to vote for.

It does, however, make me want to vote for John McCain for president. He's a combat vet, too.

There's something about the nature of ultimate human struggle — and there's no struggle more ultimate than betting your life on your tribe — that informs men and women in ways that transcend homemaking, Wall Street trading, or adrenaline sports. You learn things about yourself that not even raising a teenager can teach.

You learn to keep faith with your compatriots. The guys around you — those who don't lose their dignity or humor, and that's most American servicemembers by a long shot — become your lifetime buddies. You may not see them again for years, because every reunion risks bringing as many tears as bad jokes and rehashed war stories, but they're your family forever. You never leave your buddies behind. Other people don't quite understand.

Then there's what we don't much talk about, that whole PTSD thing. Post-Traumatic Stress Disorder sounds like something made up to keep psychology grad students busy, or maybe a seeping malfunction of our secret girly parts.

Actually, PTSD consists of adaptive physical changes to our brains. Coarsely put, we sustain significant atrophy of the neurological structures that allow us smoothly to form memories of the immediate past.

PTSD is not a weakness. It's a survival mechanism to get through hard times, and it works — but it leaves survivors erratic, forgetful, capricious, and snappishly intemperate. Vets (and others) with PTSD don't "recover" anymore than one would recover from a traumatic amputation. They adapt. You can trust me on this. Alternatively, you could check with any qualified Veterans Administration counselor, or with my patient and loving wife.

John McCain is a brother in arms. Naturally, I want to support him. I supported him during the Republican primary of 2000. Since then, Sen. McCain enthusiastically supported the Iraq campaign — but he voted against upgraded armor for troops there. He decried abysmally foul conditions at Walter Reed Army Hospital but voted against expansion of VA funding — and in favor of continuing the private outsourcing that resulted in moldy mattresses for wounded soldiers in the first place.

Whether Senator McCain has ever received treatment for PTSD is a mystery. His medical records are a closely guarded secret. What seems clear is that he suffers some symptoms — erratic decision-making, flaring tantrums of inappropriate temper, wandering forgetfulness — that are characteristic of PTSD. I don't pretend to be a psychologist, but for John McCain (or any man) to have undergone the deadly explosions on the USS Forrestal — let alone suffered five years of brutal torture — would make a prognosis of severe and continuing PTSD nearly inevitable.

Pundits have called Sen. McCain's body language during the first presidential debate "arrogant" and "dismissive." That's not how I saw it. To me, John looked like he was flinching away from a physical beating.

John McCain, canny and maneuvering senator, is a man I can respect. John McCain, captain USN (retired), is a veteran whose service I revere. President John McCain, commander in chief of the armed forces of the United States of America, is an administration I wish not to see.

John McCain's opponent, while coming out against the Iraq conflict (using a rationale of expense and difficulty that has since been vindicated many times over), has continuously voted to expand care for injured veterans. Thanks in part to Sen. Barack Obama's efforts, veterans have access to needed care for PTSD.

Veterans like myself, and veterans like John McCain.