Evinnra, I think that a soldier may hold the use of violence in an uneasy tension with himself. Perhaps some people do become soldiers even police officers because they have a violent nature/interest and know this is an "acceptable" path to use it. It is not unheard of for either soldiers or police officers to have problems with domestic violence. Hopefully those members are the exceptions to the rule.
To me a significant difference between Soldier and Terrorist may be in the timing in the resort to violence. Hopefully a soldier waits upon his government to undertake other actions to resolve issues prior to deploying him to fight and into, I think, areas already experiencing violence. I believe terrorist are deployed as a first approach to an issue, even to "promote" an issue.
It is sad to think that our nation which not only puts forth the idea of free speech, but values it so prominently/apparently should be the victim of terrorist attacks. (Our nation even hosts the UN.) Reveals the other as seriously stressed, troubled (in a couple of ways) and having a crisis of faith- even discipline.
Are we so bad at listening?
Excellent point Lizpete! Indeed it is very very strange that the United States - that was possibly the first country on the face of this planet to legislate the freedom to voice dissent - should be the target of terrorist attacks. As you say, it is perhaps the 'listening skills' of the US government that is to blame. (Listening to its own citizens and to the citizens of the global community that its reputation for fairness is fast diminishing.)
However, on the other two points you make I'm not sure we can agree. In my experience it is usually the most decent 'bloke' of the community who will enlist to be a soldier or a police officer. What kind of soldier/police officer he becomes later is totally dependent on the organization he joins. If the armed forces or the police of a country is corrupt, disorganised, violent and do not uphold laws of common decency in my experience decent blokes either become corrupt and violent them selves or simply leave. (For example the forced prostitution of young soldiers by their superiors in the Russian army - just recently coming to light - makes me wonder what image the mighty Red Army gained by this in comparison to the truly heroic image it had even in its enemies eyes. If I was the chief of the Red Army, I'd PUBLICLY HANG these corrupt bastards who made this crime against young men possible!)
To be honest I do not know a single terrorist so I do not know what makes a terrorist conspire against 'order'. Rebells are said to hold the view, which you've just mentioned, that the only diferrence between them and soldiers is 'timing', but I can not agree with this. (Especially not in countries where free speach is possible.) Whether a country is run as a democracy, oligarchy, theocracy or monarchy, there are always some legitimate means to voice concern. If all else fails, people can gather support for their cause and organise a boycott, like black americans boycotted public transport in the US. The civil rights movement in the US was very powerful precisely because people found a way to rebell without incriminating them selves in the process. WHAT we fight is not as important as HOW we do it.
By the way, I have this inexplicable feeling that the large number of suicides and mental/psychological problems occuring after serving in the Iraq war (in Australia so far we had four cases of suicides AFTER these soldiers returned home from active duty) is due to the immunisations the soldiers receive before getting there. I could be totally wrong, its just an intuition which I have no rational reason to support what so ever. What soldiers experience on the front line should be much more obvious contributor to their declining mental health, however, this intuition just doesn't seem to leave me alone.