On Aug. 27, I was transported to Vietnam on a chartered commercial airplane. We stepped onto the tarmac into steamy heat, equipped with uniforms that had been designed for a war in Europe. Tropical fatigues and jungle boots were not in the regular supply chain yet. We were also unprepared in ways far more serious than just our gear.

My infantry unit was conducting search-and-destroy missions in Tay Ninh Province near the Cambodian border. “Search and destroy” sometimes seemed euphemistic for the Army using us as bait to lure enemy soldiers out of hiding. At 26, I was relatively old for my unit, and one of my 19-year-old medics jokingly called me Pops. My forward aid station was about 500 feet from the perimeter machine guns. I was the only one who seemed concerned that I had been issued an M16 rifle and a .45-caliber pistol but had virtually no weapons or combat training. Medical personnel were instructed to carry weapons in the field and to not wear the red cross insignia. Our command believed that we were specifically targeted by the Viet Cong. After the first few weeks, I carried only a holstered sidearm. It seemed more likely that I would injure myself or one of my buddies with my M16 than any of the enemy.

By late December, Karen’s romantic letters had gradually become less frequent. She had told her boyfriend about our hospital romance, and her anxiety and ambivalence about our relationship became more acute. Then, just after the new year, a sensitive but final letter of apology told me that she was engaged to be married that summer. This was not a surprise, but it was deeply disappointing. I loved her and wanted her to be happy, but I also wanted her with me, not with someone else. It seemed particularly ironic that the chaplain who performed her wedding ceremony was my drinking buddy, and the obstetrician who eventually delivered her babies was my intern partner and best friend.

I carried Karen’s photo for luck while I was in-country, but I no longer looked at it. It was time to move on from this failed relationship and focus on more immediate issues. My life and the lives of men in my unit were at risk, and I was responsible for treating life-threatening injuries with novice skills and little more than the contents of a medic’s bag. There was also the dilemma of knowing that each time I declared my patient well enough for duty, I might be writing a prescription for his death.

When I returned to the United States, I didn’t try to find out about Karen or her newly married life. It seemed inconceivable that our brief infatuation at the hospital had occurred just one year earlier. I started dating again and met the woman I would eventually marry and raise two children with.