In the case of Afghanistan, we’re sending them off to fight and possibly die in support of a government that is incompetent and riddled with corruption and narcotics traffickers. We’re putting them in the field with Afghan forces that are ill trained, ill equipped and in all-too-many instances unwilling to fight with the courage and tenacity of the American forces. And we’re sending them off to engage in a mishmash of a mission that alternates incoherently between aggressively fighting insurgents and the admirable but unachievable task of nation-building in a society in which most Americans are clueless about the history, culture, politics and mores.

In a confidential assessment of the war prepared for President Obama, General McChrystal wrote: “The weakness of state institutions, malign actions of power brokers, widespread corruption and abuse of power by various officials and [the American-led NATO force’s] own errors have given Afghans little reason to support their government.”

A friend of mine who lives in South Carolina sent me an e-mail about a young serviceman in civilian clothes whom she and her husband noticed as he talked on a public telephone in the Atlanta airport last week. He was 19 or 20 years old and quite thin. His clothes and his shoes were worn, my friend said, but the thing she noticed most “was the sadness in his eyes and his sweet demeanor.”

The young man was speaking to his mom in a voice that was quite emotional. My friend recalled him saying, “We’re about to board for Oklahoma for the training before we move out. I didn’t want to bother Amber at work, so please tell her I called if you don’t think it will upset her too much. ... I miss you all so much and love you, and I just don’t know how I’ll get through this.”

At the end of the call, the serviceman had tears in his eyes and my friend said she did, too. She wrote in the e-mail: “I stood up and wished him good luck, and he smiled the sweetest smile that has haunted me ever since.”

As President Obama tries to decide what to do about Afghanistan, reality is insisting that he take into account the worn-down condition of our military after so many years of fighting in Afghanistan and Iraq, and the soaring budget deficits and sky-high unemployment numbers here at home in a country that is hurting badly and could use its own dose of nation-building.

Mr. Obama, in the face of these daunting realities, is said to be re-thinking his plans to ratchet up American involvement in Afghanistan. One can only hope.