That passage refers to a specific battle, not religious policy for all time.
A common misconception. While that passage refers to a specific incident in which a treaty was broken between Muhammad's forces and a specific set of pagans, it's taken by Wahabbi and other hardline interpretations of Islam to mean exactly what is says. The fact that Muhammad himself did this is evidence that it is the correct course of action. While some scholars point out that this was done during time of war, Wahabbi scholars are quick to point out that this is a time of war.
The historical context is, of course, fascinating, but entirely irrelevant to 2006, in which the Wahabbi version of Islam is subverting the other forms, and pushing itself into conflict with the West.