our violence is always justified.

Of course this is false. I hope you are not attributing these statements toward me. On the contrary, I am saying that justice must be determined individually and not based upon whatever arbitrary group someone may belong to.

What I mean is that people tend to have an easier time justifying the violence done in the name of their own group.

The German people were told that jews were attempting to destroy their country, It was kinda hard to justify defending people doing that.
The Israelis are convinced that the palistinians are out to destroy their country... It's kinda hard to defend people doing that.
Palestinians are convinced that israelis are out to destroy their homeland. It's hard to defend people out to do that.
US citizens are convinced that the Muslim world is out to destroy their country... It's kinda hard to justify defending people doing that.
Iraqis are convinced that the US is just out to steal their oil It's hard to defend people killing Iraqis to do that.

The point about terrorism becoming it's own justification is that people use the terrorism comitted in the name of the other side to justify the terror inflicted by their side. after a while the original source of the dispute becomes almost (or actually) irrelevant.

You've effextively proven my point, trying to justify the violence committed by the US "In it's defence".

So now can you see the cycle of justification and violence and terror?

The violence always seems justified when we do it.

It's never terrorism when it's doen by our side.

But who we is and who they are is always relative to the speaker.