Rationalist
Hail Voltaire
Do you deny that it is immoral to initiate the use of force (through physical violence or fraud) against others?
WTF???? Where have you been? Welcome back, man!
To answer the question: I feel that a certain degree of coercion is necessary for civilization to thrive. Examples would be taxation, police power, and eminent domain (although this is often abused). But the way you phrased your question seems to indicate force between individuals, which is only morally acceptable when it is done to thwart another act of coercion. For example, if someone breaks into my house and I feel there is a threat, it is not immoral for me to kill the fucker.