In 2004 Australia secretly installed listening devices in Timorese cabinet rooms in order to gain advantage in bilateral treaty negotiations. This is the accusation levelled by Timor-Leste in ill-fated proceedings at the International Court of Justice ('ICJ'). (1) Spying during negotiations constituted bad faith, Timor-Leste argued, and the treaty was therefore void ab initio. (2) While this argument proved unpersuasive to the Court, the proceeding represents a ground-breaking of sorts. Never before had the ICJ been asked to consider the question of states' covert information gathering, or espionage. (3)
The legal status of espionage is sometimes described as a paradox, (4) referring to the inconsistency between its clear illegality at municipal law, and its much-debated legality at international law. All states prohibit the theft of their secrets under domestic law. (5) Yet states have always practiced covert surveillance on both individuals and other states. (6) A 'paradox' can be defined as an absurd, self-contradictory or strongly counterintuitive proposition, which after investigation proves nonetheless to be well-founded or true. (7) While at first blush states take a contradictory approach to espionage, the investigation into espionage under international law has been insufficient. This paper seeks to address that gap.
Inquiry into peacetime espionage poses particular problems to the international legal scholar. There are no treaties codifying the law. There is no customary law: (8) a paucity of opinio juris runs in the opposite direction of the abundant state practice. (9) And that is only the practice we know about. It barely needs stating: espionage is a success when nobody knows it has happened. This paper will compare available peacetime state practice with the treaty and customary law of armed conflict applicable to spies. After establishing that states follow armed conflict custom in peacetime practice (Part II), the most highly qualified publicists' interpretation of the practice will be critically examined (Part III). Using the principles raised in those teachings, and applying those principles to state practice, the legality of peacetime espionage, through the example of Timor-Leste v Australia, will be considered (Part IV).
II Espionage in Treaty, Custom and Practice
The customary and treaty laws governing armed conflict define espionage and its legal consequences, broadly replicated in state practice.
The act of wartime espionage is not illegal. Gathering information on the territory of the enemy state in order to gain military advantage is a normal and accepted part of war. (10) The act's legality depends on the means used. The act is illegal when information is gathered 'secretly, in disguise or under a false pretence'. (11) This quality of secrecy transforms otherwise legal information gathering into illegal espionage under the customary law of wars, codified and still applicable today. (12) Scholars agree that the same quality of secrecy sets espionage apart from states' ordinary information gathering in times of peace. (13) This broad definition, from wartime custom and peacetime practice, is adopted in this paper.
Espionage has particular consequences under the law of armed conflict. Captured spies are not afforded prisoner of war status. (14) Instead, they are customarily subjected to summary punishment. (15) But if the spy's mission is successful their liability vanishes. Should a spy complete their mission, returning to their regular army before capture, prisoner of war status will be afforded, as it is to all uniformed officers. (16) This custom, too, is codified in treaty and still applies today. (17) Liability depends not on the action of gathering or even the means employed. Liability depends instead on where the spy is at any given time. 'Our spies are patriots,' writes Commander Roger D. Scott, of the United States' European Command. (18) 'Skulking criminality,' (19) attaches only those spying on us--whoever 'we' happen to be.
Scholarship does not distinguish between state practice in times of war and peace. There is almost no distinction in state practice. While in war captured spies are liable for the death penalty, spies captured in peace may be treated to the harshest punishment under municipal law. (20) The peculiarity of this practice is more apparent in peacetime. In peacetime, an individual carrying out the functions of their state outside its territory is not subject to foreign domestic jurisdiction. Instead they attract immunity ratione materiae. (21) But this is not true of the captured spy. States will almost never admit to sending a spy. (22) States thus avoid the question of their liability under international law: state responsibility is only incurred where the impugned act is attributable to the state. (23)
Captured spies are therefore offered no state protection and instead are subjected to the domestic jurisdiction of the target state, under which they are criminals without functional immunity. Examples of this approach in state practice can be found across the globe over centuries. (24) States' failure to assert state immunity and take responsibility for their agents' actions is not a mere oversight - it is consistent with states' silence surrounding peacetime espionage. Lord Justice Moses, drawing on Franey's analysis of the Rainbow Warrior case, (25) opined that states' failure to assert immunity is 'as much evidence of the absence of state immunity as those cases where immunity is claimed but denied by the forum state.' (26) In conformity with the law of armed conflict, spies in peacetime are personally liable if caught. States can thus avoid questions of state responsibility.
States have always covertly gathered information to their advantage, (27) criminalised individuals found stealing state secrets under domestic jurisdiction, (28) and avoided the question of state responsibility by failing to afford immunity to captured spies. This paradox is preserved in armed conflict and peace alike. (29) But what does this practice tell us about the legality of peacetime espionage?
Ill The Existing Legal Scholarship of Peacetime Espionage
The scholarship pertaining to peacetime espionage can be organised into three broad categories according to the author's opinion of the legal status of the practice at international law: (30)
peacetime espionage is legal;
peacetime espionage is illegal, or;
there are legal limits to peacetime espionage.
The first category embraces states' beloved paradox, drawing general rules from state practice. The second category avoids states' paradoxical stance by arguing that espionage is illegal under international and municipal law alike. The third category avoids the legal/illegal dichotomy, instead applying substantive rules of international law to the practice.
Peacetime Espionage is Legal
Most scholars who argue for the legality of peacetime espionage have worked for the defence force or intelligence service of their country. (31) They are best placed to access primary material regarding what states do and think. This information is critical to any analysis of an inherently secret practice, otherwise out of civilian reach. But these scholars are evidently also influenced by states' attitudes towards espionage. A great proportion of them apply states' flawed reasoning to their own analysis. (32)
The necessity for states to secretly gather information is frequently cited as a reason for espionage's legality. (33) But practical necessity is not a lawful justification for states' action in peacetime. Stone, notable for his civilian status in this category, concludes 'espionage transcends international law,' on the basis of states' reciprocal tolerance of the practice. (34) This flawed argument is taken to the extreme by Smith, a former General Counsel to the United States' National Security Agency. For him the practice of evading state responsibility means espionage is 'legal as a matter of customary international law.' (35) If Smith is aware of requisite opinio juris, to accompany the practice for custom to crystallise, (36) he has not cited it. Others who draw conclusions of law from the practice, find legality only as a matter of general principle, (37) a more methodologically sound conclusion.
When scholars of this category seek to apply international law, they overwhelmingly turn to the Lotus principle. (38) The principle is either cited explicitly, (39) or the absence of a prohibition referred to generally. (40) But this is hardly a considered application of the Permanent Court of International Justice's decision ('PCIJ'). Instead, Lotus is used as a substantive rule. Because no directly applicable law exists, scholars of this category assume that sovereignty, understood as a state's complete freedom of action, trumps all other considerations (including the sovereign equality of other states). (41) This is encapsulated by Sulmasy & Yoo who declare the 'burden of proof should lie with the critics of intelligence collection.' (42) (A more detailed analysis of Lotus and its application to peacetime espionage are considered below at Part IV).
Scholars of this category purport to apply settled principles of international law, but do so incompletely. Stone describes the fate of the captured spy as the sending state acquiring immunity when a spy is caught. (43) This neatly encapsulates the practices' reversal of the usual expected outcome under international law (that the individual is immune and the state bears the responsibility for its actions). (44) But this is not an application of international law, so much as a neutral observation made through its lens. Similarly, several scholars acknowledge that espionage could breach the principle of non-intervention, but do not apply the principle to state practice. (45) As always in this category, engagement with international law is eclipsed by...