Inter-governmental indecision on terrorism’s legal meaning is partly intentional: one man’s terrorist is another’s freedom fighter. At the UN, the General Assembly has a long-held fondness for bloody wars against colonial and racist oppressors, no matter how indiscriminate. And superpowers have sponsored subversive proxies. Terrorist tactics — violent acts intended to intimidate a population or government into conceding political demands — have long played a part in these brutish struggles. When such fighting happens a continent away it seems internecine and intractable. “Insurgency” happens in far-off lands. “Terrorism” happens at home. This glib distinction continues to forestall consensus.

Have governments now surpassed politics-as-usual in declaring war on terror? Perhaps not. “War” is an oft-used metaphor for mundane government policies. It suggests the maximum, most mobilised, response. It handily implies that an emergency exists in which liberties can be honestly abridged. The nebulous “war against drugs” — indefinitely waged by many governments — is a doleful example.

Governments seem to agree: terrorist attack is of a war-like character. But, is it actually war? The laws of war — the Geneva Conventions and customary international law — anticipate a contest between states and their armed forces for the purpose of overpowering the other so as to impose such terms as the victor pleases. Terrorists seem mismatched by this measure.

Is there then some advantage in joining fighting talk with the muscular legal regime of wartime? Unexpectedly, Protocol I of the Geneva Conventions prohibits “acts or threats of violence the primary purpose of which is to spread terror among the civilian population”. But, for terrorists, this isolated crime is their whole war.

The laws of war permit more than they prohibit: wartime is licence to murder your opponent unannounced. The sick and surrendered are protected. But civilians are safeguarded only if their deaths are “excessive in relation to the concrete and direct military advantage anticipated”. So, civilian killing can have a permitted place on the battlefield. And who is to say — us or al-Qaeda — what and where is the battlefield?

The consequence of this legal contrivance is public confusion: opposition to terrorists is enfeebled rather than emboldened. The conflation of real wars — in Afghanistan and Iraq — with the War on Terror’s rousing brandname is all but unavoidable. Military combat in Iraq and terrorism in the West have been merged (not least by US and British Governments) into a single threat under an overarching legal regime. Bombs in London become a plausible legal parlay for warfare in Iraq. No matter that Baghdad too is the daily victim of worse terrorist atrocities. War, unlike crime, is a socially legitimised activity with a chivalric history. A War on Terror inadvertently ennobles an amoral opponent and forges terrorism into an apparently acceptable tactic of wartime reprisal.

If terrorism is not and ought not to be war, then is it some comparable danger? The British Government must call it a “public emergency threatening the life of the nation” in order to derogate from the Human Rights Act. But, late last year, the law lords were unconvinced: they struck down a regime to imprison indefinitely foreign terrorist suspects. Lord Hoffmann observed: “The real threat to the life of the nation, in the sense of a people living in accordance with its traditional laws and political values, comes not from terrorism but from laws like these.” In the aftermath of bomb attacks on the capital, Tony Blair said he doubted that the same view would be held to now.

Yet, existing international law is clear: terrorists are violent criminals, not combatants. Without the connivance of existing governments they cannot conquer, capture or command a country. To wage a phony war against terrorism commits us to a legal quagmire and a strategic blunder.

A “War on Terror” perverts a highly regarded body of international law. In doing so we will upon ourselves a war where none exists, a legal code as undesirable as the organised violence that it accompanies and public sentiment more likely to appease terrorists than to resist them.

The author is legal adviser to the Civil Division European Office of the US Department of Justice. This is a personal view.

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