The terms of the pact between Dave Jensen and Lee Strunk?

From the text:

Dave Jensen and Lee Strunk did not become instant buddies, but they did learn to trust each other. Over the next month they often teamed up on ambushes. They covered each other on patrol, shared a foxhole, took turns pulling guard at night. In late August they made a pact that if one of them should ever get totally rucked up—a wheelchair wound—the other guy would automatically find a way to end it.