I was one of the first American officials to arrive in Kabul at the end of 2001. The war that seemed to be ending back then is currently in its 16th year with no end in sight, and for those of us who were there at the beginning it now sometimes seems like it was a lifetime ago. President Barack Obama not so long ago referred to Afghanistan as the “necessary war.” But now it might be more appropriate to refer to it as a “forgotten war,” as President Donald Trump has sent a few thousand more soldiers to Kabul—while also stating emphatically that he will not be discussing strategy or...

I was one of the first American officials to arrive in Kabul at the end of 2001. The war that seemed to be ending back then is currently in its 16th year with no end in sight, and for those of us who were there at the beginning it now sometimes seems like it was a lifetime ago. President Barack Obama not so long ago referred to Afghanistan as the “necessary war.” But now it might be more appropriate to refer to it as a “forgotten war,” as President Donald Trump has sent a few thousand more soldiers to Kabul—while also stating emphatically that he will not be discussing strategy or...