Ayn Rand, famous (or infamous) creator of Objectivism, considered the use of agressive force to be one of the 'destroyers of the world'. The other destroyer was faith. I'll leave off faith for another day, and focus on force.
As much as I currently disagree with much of Rand's philosophy (particularly her views on esthetics), I happen to agree that the use of aggressive force is one of the destroyers of the world; I also agree that the use of force is only ethical when it's used in retaliation to the initiation of force. In other words, I am no pacifist, and would even consider pacifism, especially if practiced by a whole society of people, not only as not ethical, but downright evil. But more of that some other time. (Short version: Pacifism, practiced on a large scale, puts innocent people in harms way. ie: It kills people.)
I've had a lot of arguments lately with various people about the respective virtues and/or dangers of words. To my way of thinking, true power lies in the exercise of reason, which manifests in words and actions; which also means, contrarily, that the opposite of reason is the exercise of brute force. For the purposes of simplicity, when I refer to brute force, let's imagine I mean fists, or weapons. It should almost go without saying, if we've learned anything as a species, that the person who is apt to start swinging his fists over the slightest disagreement, is a person who is not open to reason, but in fact, dead-set against it. These are the enemies of reason, and as such are enemies of free speech: the use of the power of words. A truly enlightened person knows that words and reason are inseparable and, in fact, co-dependent. Without words, we cannot reason.
In my experience, there are many people who are dead-set against reason. These are individuals who, in general, are so certain of the veracity of their beliefs that any disagreement, however delicately or diplomatically worded, will incite them to anger; and in some individuals this switch from normalcy to blind rage can be triggered, literally, in seconds. I have seen it happen so many times it makes my head spin: The absolute refusal, or sheer inability— I sometimes cannot determine which— to tolerate the articulation of an idea that causes these people of whom I speak to think outside the box they've locked themselves into.
Someone I know is fond of a certain expression: "Don't write a check your ass can't cash." This is a rather unfortunate little phrase that actually means: "If you think you might get hurt, don't voice your opinion." In other words, it's an explicit, if poetic, advocacy of cowardice.
"Don't run your mouth unless you can back it up", is another way of phrasing the same sentiment: If you're in a situation where speaking your mind might cause you to get your ass kicked, stay silent." No matter the street-wise manner these sentiments are voiced in, they amount to the same thing: Cowardice.
I've taken my lumps when situations have called for me to stand my ground, come hell or high water. I've got actual, literal lumps to prove it. I'm a small guy, not physically strong, and decidedly non-aggressive; but I'm also not a coward. I don't care if the person I'm interacting with is six foot ten: If they insult me, and especially if they are under the delusion that their physical advantage will intimidate me and cause me to hold my tongue, then all bets are off, and this six-foot-tenner is gonna get an earful of reality whether he likes it or not.
Naturally, Goliath will have every right to exert his strength, and in many cases I can understand that I've got it coming. But the possibility of being beaten up is a trifle when compared to the possibility of behaving like a coward.
The world is full of Goliaths (people or groups in power) who simply cannot grasp that fear of harm will not silence the people they wish to keep under their ugly, collective heel. They don't understand it, and it literally drives them crazy. They will stop at nothing in their blind attempt to silence the voice of reason with their big, hairy hands. When the voice of reason keeps on speaking, despite a bloody mouth, a black eye, or broken bones, these Goliath's get even angrier, and put even more force into their futile blows. "When will this idiot be quiet?" they cogitate, swinging away, wondering just how far they will have to go until the "idiot" finally decides to close his mouth.
The tragedy is that at some point, the voice of reason is, at long last, rendered silent, and Goliath can finally stop swinging his hairy mitts and relax. This is happening all over the world, especially in theocratic countries in the Middle East. There is sometimes a lot of blood to mop up, and maybe even some graves to be dug, but at least Goliath can rest in peace, since the silence he so dearly craves has been achieved. The voice of reason can rest in even greater peace, because it refused to be silent, even against the threat of harm or death.
Nonetheless, Goliath will stand there, scratch his rotund belly, and wonder, "Why wouldn't that little prick just be quiet? Couldn't he see that he was wrong, because he had such little hands and since mine are so big and hairy? Hmm..." The world is full of bullies, of Goliaths, individually and collectively. But there will always be those pesky little David's with their words, their slings, and their indomitable courage.