West Papua could be a good defining point.

Australia worked with the Dutch for the freedom of West Papua from 1957, helping to build their hopes for liberation sky-high.

Then when the United States played realpolitik in 1962 and used West Papuans and their lands as a way to buy a pro-Western alliance with Jakarta, we were suddenly locked into a position of viewing the people we were once helping toward liberty, now being viewed as terrorists, if they dared cry freedom.

The Indonesian rule of Papuan New Guinea has been brutal, as happened in East Timor and even now we help train their anti-terrorism unit, which happens to also be active in New Guinea chasing down any Papuan who dares to cry freedom.

So, who is the terrorist in this mix, which echos every time an Indonesian bullet strikes a West Papuan in this slow-motion genocide to our north.

We may also wonder if our behaviour toward the western Papuans is brutally racist.

Are we party to genocide?

Realpolitik is a clean word for a dirty game, which locks us all into a position of supporting terror against the Papuans of New Guinea.

Kim Peart

Interesting article on a complex issue - which turns up a bit actually - see for example the TC discussion regarding the ANZ false press release aimed at Nathan Tinkler.

The status quo - the powers that be - always regard the powers that might be - rebels, "subversives" and the like - as terrorists. From nazi murders of terrorist resistance fighters or partizans to the outraged Victorians watching the Pankhursts chaining themselves to anything in reach... these folks and their conduct are just beyond the pale - an attack on us all - a threat to our way of life. We are terrified - you should be too.

I am surprised and somewhat disappointed that we'd be reduced to straw polling academics and kids to get a "common sense" understanding of terrorism. There is actually a well-established discipline in this field, looking at the use of terror in political struggles over centuries. Doesn't look like this research and study gets much of a look in any more.

There are different forms of terrorism - different targets, priorities, messages and purposes and the choices made by terrorists reflect their political viewpoint.

To illustrate: large scale mass murder of non-combatants or the general public is designed to create a crisis of confidence and widespread fear... to precipitate a crisis of legitimacy in the state. Suicide bombers, 9/11, car bombs outside mosques.

To do this the perpetrator must regard anyone in the zone as a legitimate target - to regard them as expendable - certainly less than human. This requires a certain world view that is deeply ideological and sectional. It is the strategy of the small isolated group, seeking to show its ascendancy.

Very different to blowing up power lines and railways - attacking police or army outposts - or even conducting individually targeted acts of assassination. Yet these too are described by the State as "terrorists". Is bank robbery terrorism? The Russian anarchists used the phrase - the propaganda of the deed - to capture its essence.

Is there such a thing as "economic terrorism"? Or is terror inherently human in its scale and intent?

Perhaps it's one of those "let history be the judge" issues... that only in hindsight can the true terrorists and heroes be identified.

But I think it is possible to identify potential heroes and actual terrorists by looking at who they kill, how and why. Potential heroes tend not to blow up non-combatants or their own people - those they claim to serve - indiscriminately. There is no humanity or humanism in this.

One can put together a reasonable profile of the perpetrator by carefully studying the target and the consequences of the act. It doesn't require a poll.

"..Terrorism is some form of purposive and planned violence that has a political, religious, or ideological motivation. It is intended to coerce or intimidate and is targeted at civilians or government...."

This definition could also be applied to the use of military force, so it is a fairly poor discriminator if you are trying to specifically define terrorism. But I sympathise with the intent to define terrorism. It has been badly misused and overused in order to support political agenda - and has become almost a 'fullstop' to end debate.

Terrorism is a tactic - it is not an ideology. It has been used by western governments as well as non-state actors, and will be used again by both in the future. Misusing the term as we do just complicates our ability to deal with those who use it against us. They are not 'terrorists'. They are organisations that may use 'terrorism' as a tactic to achieve political or idealogical goals. We need to think about it in those terms.

Fergal, A most interesting and worthwhile project, And congrats on getting ARC funding for it. It is obviously irrational for states to try to legislate concerning terrorism or otherwise deal with it if they cannot define it. Not that that has stopped many states from going full steam ahead.
Another political reason states haven't yet defined terrorism is that it has so far proved impossible to produced a meaningful definition without leaving themselves liable to inclusion. For example the following two pars come from the US National Institute of Justice website:

"Title 22 of the U.S. Code, Section 2656f(d) defines terrorism as “premeditated, politically motivated violence perpetrated against noncombatant targets by subnational groups or clandestine agents, usually intended to influence an audience.” [1]
"The Federal Bureau of Investigation (FBI) defines terrorism as “the unlawful use of force or violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives.”

The first excludes states by limiting the definition to "subnational groups" and the second excludes them with the term "unlawful", ie, not approved by (state) legislation. Yet, if, as other comments have suggested, terrorism is a strategy, then whether it is carried out by state or non-state actors seems immaterial.
A further possible weakness in the above definition, and yours, is that it excludes economic motivations - such as gaining access to economic resources, like territory or oil wells. Even if we don't know what terrorism is it is safe to say "terrorism is terrorism", regardless of who does it.
To lighten up a bit, the difficulty of defining terrorism has led to two (strictly unofficial) definitions of terrorists: "swarthy opponents of US foreign policy" (from Chris Hitchens) and "bombers without an airforce". Both neatly exclude state actors while elegantly highlighting the hypocrisy of most state-sponsored definitions.