In Bruce Weigel's poem "What Saves Us," the two situations being compared is the narrator's attempt to make love to a woman the night before he ships out to war, and surviving that war.
In his fear and anxiety, the narrator believes that by making love to this young woman, that if he would die, he refused to do so never having made love to her.
The next morning I would leave
for the war and I thought...to myself
that I would not die never having
been inside her body.
The past between them he refers to as the "parking lot of the high school of our failures." We might infer that enlisting was one of the few choices open to him upon graduation. This act of making love may remind him that he is fully alive, and give him the sense that he would be protected from death—which allows us to infer that he is frightened about what will happen to him in the war.
However, before they consummate the act, they stop: perhaps his shuddering alludes to his early "culmination" before the act can be fully completed, and reality stepping in with the sound of bells going off in the hallways of the empty school.
The bells going off may foreshadow the actual fighting on the battlefield—the bells symbolic of the "rockets roaring in" in the last line of the poem.
With the end of their passionate "interlude," the young woman gives the narrator a crucifix—Jesus on the cross...
...the tiny savior's head
hanging, and stakes through his hands and his feet.
This might indicate that the narrator at the moment also feels that perhaps the war will lead to his own sacrifice—his own death. The poem's title refers to "What Saves Us," and with the gift of the crucifix and the deep, long hug that the young woman gives him, the narrator is comforted. His fear and "release" is alluded to with the phrase:
...my heart's black wings were calmed.
It is at this point that we notice the poem's turning point: the poet writes...
We are not always right
about what we think will save us.
The narrator reminisces about the time spent in the back seat of his father's car. The girl he was with he refers to as an "angel:"
I thought that dragging the angel down that night
would save me...
However, he finds that there is something spiritual that he carries in the form of the crucifix: that instead of his memory of making love with his girl, he depends on her gift, which he carried...
...in my pocket
and rubbed it on my face and lips
nights the rockets roared in.
We can assume that he is saved in that he has written this poem. He comments about the ravages of war around him, knowing that death is very close to him:
People die sometimes so near you,
you feel them struggling to cross over...
Ironically, the poem starts with images of the tangled bodies of lovers in a car, and ends with tangled bodies of war...
...the deep untangling, of one body from another.
...as their spirits struggle—also as the soldier's spirit had struggled at the beginning—but this time, the struggle comes from sorting through the dead and wounded bodies around him, while the spirits of the dead try to cross over.
We assume this crossing is spiritual between life and death. It may also mirror the soldier's individual struggle to face the prospect of death in war—crossing over from youth and innocence (believing that making love will save him) to a place where he can only depend on his faith to lift him up amid the chaos, and protect him from the same fate of so many others around him.