Communities and relationships can use this to their advantage. In a few weeks or months, the passion of disagreement over a particular issue abates to the point where the prospects for working together return.
"Time does not heal all wounds; it buries them in very shallow graves." Quoted from Robert Haney's Caged Dragons: An American P.O.W. in World War II Japan [ISBN 1-879094-06-1 (alternate, search)]
There are exceptions. Some events are so emotional and so unique that they are remembered for a lifetime. Violence, fear, and unpredictability loom large enough to be hard to forget. Passionate fights culminating in the loss of status or money are rarely forgiven and forgotten, particularly when occuring in a repeated pattern.
Incidental contact in the absence of a power disparity provides the fastest framework for eliminating the "charge" that has built up during a pattern of conflict.