What is terrorism? That is the question the Supreme Court must resolve in R v Gul. More specifically, are attacks by insurgents in a non-international armed conflict – for example attacks on Coalition forces in Afghanistan and Iraq – within the definition of ‘terrorism’ in s 1 of the Terrorism Act 2000?
The Court’s answer will have important consequences for supporters of armed insurrections across the globe. It will determine the status of resistance movements like the current Syrian uprising, and how British law treats those who champion such causes.
The Appellant uploaded videos onto the Internet showing attacks by Al-Qaeda, the Taliban and other proscribed groups on various military targets, including attacks on Coalition forces in Iraq and Afghanistan. The films praised the bravery of the fighters and encouraged further attacks.
The Appellant was charged with disseminating terrorist publications contrary to s 2 of the Terrorism Act 2006. He argued that the videos portrayed legitimate resistance against military invasions, and claimed he did not support or encourage attacks on civilians. He was therefore not encouraging ‘terrorism’, but self-defence.
The jury asked whether the attacks were terrorism within the meaning of the 2000 Act. The Judge said they were, and the Court of Appeal agreed.
The statutory definition – The Terrorism Act 2000
Section 1 of the Terrorism Act 2000 defines terrorism as the use or threat of serious violent action which:
– is designed to influence the government or an international organisation or to intimidate the public; and
– is done for the purpose of advancing a political, religious, racial or ideological cause.
The wording of s 1 is comprehensive and unqualified. The provision has a wide extra-territorial reach – it expressly includes action occurring outside the United Kingdom and action designed to intimidate the public or influence the governments of foreign countries: s 1(4).
The Appellant’s argument
The Appellant argued that, notwithstanding the broad statutory language, s 1 should be read down to exclude attacks by insurgents against a state’s armed forces from the definition of terrorism. In support, he relied on the distinction in international humanitarian law (the law of armed conflict) between attacks on the military and attacks on civilians.
Judgment of the Court of Appeal
The Court of Appeal considered whether international law demanded a restrictive interpretation of s 1:
‘The issue for us is whether, under international law, the definition of terrorism under customary international law has developed so that an attack by insurgents on military forces of a government is not terrorism.’ 
Some international instruments exempt those engaged in wars of liberation or self-determination from the definition of terrorism. For instance, The Convention of the Organisation of the Islamic Conference on Combating International Terrorism provides that: ‘Peoples struggle including armed struggle against foreign occupation, aggression, colonialism, and hegemony, aimed at liberation and self-determination in accordance with the principles of international law shall not be considered a terrorist crime.’ Similar qualifications are found in Canadian and South African criminal law. By contrast other legal instruments, such as the Australian Criminal Code Act, contain no such exception.
After reviewing the relevant state practice, the Court of Appeal concluded that under international law terrorism was not confined to violence against civilians:
‘although it is clear that in all forms of armed conflict civilians should not be attacked, that does not amount to state practice or opinio juris that those who attack military personnel in non international armed conflict cannot be designated as terrorists’ 
While international law may, in future, develop a rule that excludes some types of insurgents from the definition of terrorism, ‘the necessary widespread and general state practice or the necessary opinio juris to that effect has not yet been established’ . Accordingly, nothing at present exempts those who attack the military during an insurgency from the definition of terrorism .
Domestic law, likewise, pointed towards a broad interpretation of terrorism. Cases from the asylum field were not directly on point, while in R v F  EWCA Crim 243 the Lord Chief Justice held that, given the wide terms of s 1, there was no exemption for terrorist activities motivated by an allegedly noble cause.
In these circumstances the Court of Appeal concluded that:
‘The definition in s 1 is clear. Those who attacked the military forces of a government or the Coalition forces in Afghanistan or Iraq with the requisite intention set out in the Act are terrorists. There is nothing in international law which either compels or persuades us to read down the clear terms of the 2000 Act to exempt such persons from the definition in the Act.’ 
Insurgents, terrorists and freedom fighters
Defining terrorism is notoriously difficult: one man’s terrorist is another’s freedom fighter, as the aphorism goes. The Court of Appeal’s judgment leaves no scope for exempting freedom fighters – or those who support them – from the reach of UK terrorism legislation. Any politically motivated insurrection is terrorism, no matter how tyrannical the regime under challenge.
In many cases this is unobjectionable, however it may also produce some surprising results. On the Court of Appeal’s analysis, Syrian insurgents fighting against the Assad regime are engaged in acts of terrorism within the meaning of s 1, as were the rebels who overthrew Colonel Gaddafi in Libya. So posting a video glorifying attacks on the Syrian army may be a terrorist offence, even while the British Government openly discusses arming the resistance.
During the Terrorism Act’s passage through Parliament the Home Secretary said it was fanciful to suggest (for example) that supporting Kurdish insurgents against Saddam Hussein would be prosecuted as terrorism. However prosecutorial discretion is a poor substitute for legal clarity. If supporting ‘genuine’ freedom fighters is allowed, then this ought to be enshrined in law rather than entrusted to the choice (and political judgment) of prosecuting authorities.
On the other hand, excluding all insurgent-on-military attacks from the definition of terrorism would be a strikingly narrow construction of a deliberately broad provision. Resolving these tensions is difficult. The Court’s judgment is therefore keenly awaited.