Joshua Fit De Battle

The chorus I'm in recently started learning an arrangement of Joshua Fit de Battle of Jericho, a song that my daughter also performed in her chorus last year. She was surprised by the differences between the two arrangements, so we looked up some other performances on youtube (would you believe Elvis Presley, of all people, did a recording of it?) In the process we got to talking about the story behind the song, which I didn't remember well enough to share with her, so we looked that up too.
Reviewing the story of Jericho reminded me of just why it is that Christianity has such a hard time championing the "good" side of "good vs. evil."
Joshua came out of the wilderness with the Israelites, taking over leadership of the tribe after Moses' death. Their ancestors had been slaves in Egypt, and they were still living as nomads two generations after their escape. But when Joshua succeeded Moses, they went to the city of Jericho, invaded and conquered that city, and murdered every man, woman, and child who lived there before moving in themselves. The one exception was the family of a woman who had given them aid in spying on the city before the attack. She did this not because she thought their cause was right, but because she was afraid of them.
So when we celebrate Joshua, we're celebrating unprovoked violence. We're celebrating genocide. We're celebrating the oppressed rising up, not against the oppressor, but against innocent bystanders. We're celebrating a moral standard that justifies murder and theft, done purely for selfish ends. And we are celebrating the might of a God who not only condones such behavior, but commands it and helps his people succeed at it.
The song is still exciting and engaging to sing, but I'm having serious reservations about its moral content. At a guess, I'd say that most people who read this story gloss over its barbarism, and either invent rationalizations for it or avoid the subject entirely. But it's a bit like keeping a land mine in the back yard, don't you think? Its presence in the center of the accepted canon of God's Word leaves open the eternal possibility that some day, Christians will return en masse to a morality that condones expansionist genocide.