"I wanna be bigger, stronger, drive a faster car..."

In American culture, strength basically means decisiveness and perserverance. A lot of value is based on independence, "pulling yourself up by your own bootstraps," and such, and these are the two qualities really needed to succeed at being an individual.

Nietzsche argues that strength is seeking power at all costs. To him, strength is acting out immediately any compulsion to overpower, to master, to subject the weaker; and this is also seen in his praise of the "nobility" as the originators of superior morals before they were corrupted by the Jews.

Achebe's strength was far more balanced: though a lot of it was purely physical, strength was intended to be used for the community, in addition to the individual.

peace in, war out - Hunter