I’ve already criticised what I think is a fundamental contradiction undermining the Court of Appeal’s judgment in the Miranda case. But there’s another aspect of the judgment that I must mention, which may well be of more lasting importance.

The power used to stop and question David Miranda is conferred by paragraph 2(1) of Schedule 7 of the Terrorism Act 2000:

An examining officer may question a person to whom this paragraph applies for the purpose of determining whether he appears to be a person falling within section 40(1)(b)

such a person being defined by section 40(1) which provides that a

“terrorist” means a person who …

(b) is or has been concerned in the commission, preparation or instigation of acts of terrorism.

Deeper in the legal labyrinth, the definition of “terrorism” is in Section 1:

(1) In this Act “terrorism” means the use or threat of action where—
(a) the action falls within subsection (2),
(b) the use or threat is designed to influence the government or an international governmental organisation or to intimidate the public or a section of the public, and
(c) the use or threat is made for the purpose of advancing a political, religious, racial or ideological cause.

(2) Action falls within this subsection if it—
(a) involves serious violence against a person,
(b) involves serious damage to property,
(c) endangers a person’s life, other than that of the person committing the action,
(d) creates a serious risk to the health or safety of the public or a section of the public, or
(e) is designed seriously to interfere with or seriously to disrupt an electronic system.

So the purpose of stopping and questioning David Miranda was, according to the framework laid down by this legislation, to see if he was a person concerned in terrorism, very widely defined.

Applying this definition of terrorism on its face, as I wrote in 2013, you might well argue that publishing the content of sensitive intelligence-related documents could “create a serious risk to the safety of the public”, and so satisfy section 1(2)(d). The Guardian’s arguably campaigning use of the Snowden documents could be said to advance a political cause, satisfying the section 1(1)(c) condition: a political cause need not be a malign one. And you might say use of the documents by the Guardian to create a public debate is “designed to influence the government” as required by section 1(1)(b).

The apparent width of the definition of terrorism here is a matter of concern. I thought the argument made for David Miranda in the first instance judicial review proceedings had some force, and I noted examples his counsel Matthew Ryder QC gave:

Firefighters threatening to strike, he said, would endanger life, would want to influence government and would be taking political action. Were they terrorists? Or if government had a secret plan to keep us all safe by installing cameras in every home, an investigative journalist revealing the plan might risk lives (remotely at least) in an attempt to have political influence.

Ryder didn’t succeed with Lord Justice Laws, but took a similar approach on appeal (see para. 46 of the judgment):

Mr Ryder gave another example: a group of junior doctors wishes to erect a sign to protest about Government policy towards the NHS. Inadvertently, some members of the group erect it in a way that accidentally endangers the life of a passer-by. Mr Ryder submits that, if the literal interpretation of “act of terrorism” adopted by Laws LJ is right, the junior doctors erecting the sign with a political message have committed acts of terrorism. They have taken an action designed to influence the Government to advance a political cause, which (even if entirely unknown to them) endangered the public or created a risk to health and safety.

And now, on appeal, Matthew Ryder has succeeded in persuading the Court of Appeal to depart from pure literalism and to read some mental element in to the definition of terrorism.

At paragraphs 51-2 of the judgment, Lord Dyson says

First, the literal interpretation involves according to the word “terrorism” a meaning which is far removed from its ordinary meaning … Secondly, the fact that the literal interpretation potentially gives rise to unpalatable consequences … raises a serious question as to whether it can have been intended by Parliament … Thirdly, the interpretation does not reflect the aim and intention of the promoters of the Bill as expressed to Parliament.

In my view, these three factors when taken together provide a powerful reason for rejecting the literal interpretation.

Lord Dyson looked at section 1(2) in particular, and chopped it into three “categories”: the first category, subsections 2(a) and (b), covers threatened action which—

(a) involves serious violence against a person

or

(b) involves serious damage to property

As far as these are concerned, he said (para. 53)—

It is not an ordinary use of language to describe a person as being “involved” in violence or damage to property if he is not aware that he is being so involved or if what he does is accidental. On this point, I respectfully disagree with what Laws LJ said

In relation to the third category, covering threatened action which—

(e) is designed seriously to interfere with or seriously to disrupt an electronic system

Lord Dyson said (pra. 54), tying his thinking to the first category also, that

The third category of action is … clearly defined by reference to the state of mind of the actor. For the reasons that I have given, I consider that the first category of action must also be considered as importing a mental element.

That left the second category, covering threatened action which

(c) endangers a person’s life, other than that of the person committing the action,

or

(d) creates a serious risk to the health or safety of the public or a section of the public, or

About this Lord Dyson said (para. 54):

I accept that, on a literal interpretation, the second category could include acts which endanger a person’s life even if the actor is not aware that they do. But such an interpretation would dispense with the need for a mental element in the second category, whereas it is required in the first and third categories. It is unlikely that Parliament would have intended to make such a distinction between the three categories. If Parliament had intended to provide that a person commits an act of terrorism where he unwittingly or accidentally does something which in fact endangers another person’s life, I would have expected that, in view of the serious consequences of classifying a person as a terrorist, it would have spelt this out clearly.

Lord Dyson sees all of the types of threatened action in section 1(2) as requiring some mental element, then. In order to be concerned in terrorism, a person must be at least reckless as to causing serious violence or damage, danger to life, or risk to health and safety; or else design to interfere with or disrupt a system. The legal definition of terrorism has been significantly narrowed.

It’s important to note that Lord Dyson made clear (para.55) that

It does not follow that publication of material cannot amount to an act of terrorism. If (i) the material that is published endangers a person’s life (other than that of the person committing the action) or creates a serious risk to the health or safety of the public or a section of the public; and (ii) the person publishing the material intends it to have that effect (or is reckless as to whether or not it has that effect), then the publication is an act of terrorism, provided, of course, that the conditions stated in section 1(1)(b) and (c) are satisfied.

And this ruling on the meaning of terrorism, not having been decisive in the appeal, does not in itself create legally biding precedent for the courts of the future. Nonetheless, if it is followed—particularly if it is approved on this point by the Supreme Court, which seems to me likely—this may represent the most important aspect of the case, and a significant victory for critics of Britain’s tough terrorism legislation.

Which no doubt explains why the independent reviewer of terrorism legislation, David Anderson QC, thinks this is an important ruling: