In The Sun Also Rises, how is Jake's sexual impotence a metaphor for three characters' powerlessness in the novel?

The impotence that Jake
suffers from acts as a very powerfulfor the way that war had changed perceptions of masculinity
and challenged what it was to be a man. Whereas before, war was a matter of personal valour and
bravery in the face of the enemy, the reality of trench warfare in World War I where thousands
died without even facing their enemy thanks to gas attacks and bombs profoundly challenged what
it was to be a man, as survival seemed to be based more on luck than on any other objective
characteristic, such as skill. Jake, significantly, is rendered impotent thanks to an injury
sustained during the war, and this therefore represents the challenge to masculinity that World
War I represented. However, at the same time, it also acts as a kind of symbol of the so-called
"lost generation," or the aimlessness of the young men and women who, having
experienced war, found themselves unable to engage with life and wandered around aimlessly,
without purpose or goal. This aimlessness is expressed in a variety of ways in the novel, but
most importantly perhaps through the constant drunken carousing and debauchery of the
characters. Jake himself picks up on this aimlessness when he says to Cohn, after Cohn expresses
a desire to move to Spain from Paris, that the real issue isn't his current location but an
internal problem:

You cant get away from yourself by
moving from one place to another.

Jake inherently
recognises that the problem with the lost generation is something internal rather than external,
just as his impotence is external and external. Jake, just like the other main characters, shows
that he is unable to commit to a meaningful relationship and be productive in society, and his
impotence acts therefore as a metaphor that characterises the failings of the main characters:
all are impotent, in their own different ways.