Explain the ending of True West.

I think the ending of True West by Sam Shepard shows the brothers becoming part of the West. Their mother's kitchen seems to fade away as "the figures of the brothers now appear to be caught in a vast desert-like landscape." This change in setting shows them becoming part of the wild outdoors. Also, their actions reflect their wildness. Throughout the play the brothers have argued and fought, but this comes to a peak at the end when Austin strangles Lee with a telephone cord. At first Lee appears to be dead, but then he gets up. They square off, and "they are very still but watchful for the next move." This makes me think of a standard Western film, where two cowboys stand across from each other, wondering who will make the first move.
The ending also makes me think of the Biblical story of Cain and Abel. Cain murders his brother Abel out of jealousy, and God punishes him to a life of wandering. The image of the two brothers standing across from each other also makes me think about how similar they are. They start off the play as very different characters, but here they are together at the end with the same animal instincts.