It wasn’t the fact that a young man had been killed that made me stop.

The unfortunate truth, after all, is that young men are frequently killed. So, in itself, the shooting of 20-year-old Ibrahim Khoury in Coral Gables, Fla., seemed sadly … ordinary.

No, the thing that demanded a double-take was the professed reason he was killed.

According to a story published last Thursday in The Miami Herald, Khoury was an altar boy and engineering student who dealt pot on the side. Miami-Dade police say he and his cousin, George Khoury, had the misfortune to encounter three prospective customers, all teen-agers, who had no intention of paying for their purchase. When Ibrahim Khoury handed over the bag of marijuana, one of the teen-agers, 18-year-old Andres Carvajalino, allegedly pulled a gun and pointed it at Khoury’s forehead.

George Khoury dared him to shoot. Meanwhile, Ibrahim snatched the bag away. And Carvajalino, according to police, shot him instead.

Why?

“He felt his manhood had been challenged.” That’s how Detective Jeff Lewis explained it.

Carvajalino could not, in other words, have maintained his good opinion of himself, could not have walked with his back erect and his head high, had he not allegedly fired the gun. Had he not pulled the trigger, he would have been less than a man.

God help him. God help us all.

For generations, the ability to access violence has been one of the primary ways we defined manhood. From John Wayne to to Bruce Willis, the iconic man, the one boys were taught to celebrate and emulate, was the one who was good with his fists. A principled fellow, deeply moral in his way, a good-tempered sort who would never be the one to start trouble. But, oh, could he finish it. If you got on his bad side you were, as they used to say, cruising for a bruising.

We could argue ad infinitum about the appropriateness of that model. Deliberate the need to champion other means of conflict resolution against the reality that some enemies Osama bin Laden is a better-than-average example will not respond to any coercion short of violence. But in the end, the debate is academic, because the model is obsolete.

Many boys and young men have, in a sense, cut to the chase. Forget the stuff about principles and morals and good temper when do we fight? When do I get to prove that I can handle myself? When do I get to show that I am a man?

Our cities are full of boys, some much older than 21, desperate to prove that they’ve crossed that invisible line. Boys figuratively and literally tugging on their crotches, packing weapons in their waistbands, swaggering through life, in the expectation that somehow this will make them men.

The curious thing is, while the old model of manhood certainly included the capacity for violence, it was never limited to that. It also involved the willingness to take a stand, the love of competition, the ability to provide for a family and the confidence that comes of feeling that one is simply … capable. Equal to the challenges of life.

Manhood meant those things, too, back in my day. But this is a new day, and for many would-be boys-to-men, the capacity for violence is all that’s left, the one reliable means by which to demonstrate their manhood. Can any of us be surprised? We’ve minimized the importance of the lessons men teach boys. It has become politically correct to consider mother and father not just equal, but interchangeable.

The fallacy of that thinking can be seen in the faces and lives of a thousand lost boys searching for a shortcut to something they only dimly understand. But there are no shortcuts to the real thing. Neither prodigious violence nor prodigious sex will get you there. This is what we need to help our sons to see.

Otherwise, there’s a danger that many more will end up like Andres Carvajalino, doing some stupid and irreversible thing to protect their manhood. Wrecking lives to defend something they never truly had.

Leonard Pitts Jr. is a columnist for the Miami Herald.