Dave Jensen and Lee Strunk didn't become fast friends but they started to trust each other more over the next month as they teamed up on ambushes, covered each other when patrolling, shared foxholes, and took turns on guard at night.
Now that they are "square" after the events of enemies, now that they have a firm foundation of knowing they won't try to kill each other, Jensen and Strunk can forge real trust.
In late August they made a pact that if either were to ever get terribly wounded so as to have to end up in a wheelchair, the other would automatically end the wounded one's life. They wrote it out and signed their names, with others acting as witnesses.
This pact they made becomes their personal social contract, obligating the other to act in the event of injury. They believe it would be better and fairer to die than live maimed.
In October, Lee Strunk stepped on a rigged mortar round which blew off his right leg at the knee. At first he seemed to be hopping as though he stubbed a toe, but then he panicked. He tried to run and fell. The stump of his leg twitched, and blood erupted in spurts. He seemed shocked, passed out, and Rat Kiley administered a tourniquet and morphine, then ran plasma into him.
Death comes suddenly, out of nowhere. Strunk's fear after he loses most of his right leg is perhaps not only from the shock of the event itself, but from the fear of having to die after signing off on the pact he made with Jensen.
As they waited for a chopper, Dave Jensen went to Strunk's side. The stump wasn't twitching anymore and not everyone was sure if Strunk was still alive. He finally opened his eyes and looked at Jensen. He moaned and tried to get away, begging Jensen not to kill him. Jensen told him to relax, but Strunk was confused. He pointed at his leg and said it wasn't that bad, they could sew it back on. Jensen agreed. Strunk passed out again and when he woke up he said, "Don't kill me." Jensen said he wouldn't, but Strunk made him promise and swear to him. Jensen abided.
Strunk is terrified to see Jensen because he immediately thinks of their pact, and begs for his life. When he wasn't facing death he couldn't imagine living as a maimed person. Now, facing death, he would rather live maimed—he just wants to live. His will to live overpowers any pact he'd made with Jensen. For his part, Jensen agrees not to abide by the pact.
Strunk was taken to the chopper when it arrived. Jensen touched Strunk's good leg and told him to "Go on now." Strunk died somewhere over Chu Laid, which O'Brien notes seemed to free Jensen of "an enormous weight."
Strunk's death is a relief to Jensen because it allows Jensen to remain a man of his word—he no longer has the obligation to kill Strunk (even if he would never have actually done it).