Good point Dimension X about the "father/son" relationship between Wayne and Clift. Somewhat akin to Luke Skywalker and Darth Vader from Star Wars. When it came right down to it - even though they were blood enemies - Vader could not see his own son killed. Growing up, some of the most vicious fistfights I ever witnessed were between brothers; though they would have fought till the sun set unless they were stopped, stopping the fight was actually quite easy, just a matter of stepping between the two. It's sort of like they both wanted the fight to end but stubborn pride prevented either from calling it quits, but when given an excuse, they simply stopped. The next day they were back to being brothers again like nothing ever happened. Maybe that is why I readily accept Red River's ending. Wayne and Clift were family for all intents and purposes, and as the saying goes, "there's a thin line between love & hate", Joanne Dru's speech afforded them an "easy out" to step away from hate and over to love. Though I should watch the film once again just to make sure my recollection of the ending fits with the above. Finally for all our speculation, Dimension X is probably right when he wrote "Then again, maybe it was just an audience tested studio ending forced onto the film makers in order to make a more commercial product."