The Application of the Traditional Concept of Neutrality to Modern Means of Warfare

space update

Neutrality, in its traditional sense, was activated when conventional war broke out and was limited to neutral states refraining from taking part in active hostilities by not taking any sides during the conflict.  However, with the rapid advancement of technology and new discoveries, conventional warfare has undergone significant transformation over the years. Post World War II, conventional warfare has been replaced by other modern means such as nuclear, space and cyber warfare. The concept of neutrality has evolved with the changing international system and adapted itself to the dynamic practices of war and security prevalent today. This research note aims to analyze the application of the traditional concept of neutrality to such non-traditional means of warfare in the context of the 21st century with its shifted focus on promoting equality of access and responsibility between states in times of peace as well as conflict.


The concept of neutrality emerged from a desire of states to refrain from being involved in wars waged by other states. In its simplest form, it is defined as a “policy adopted by countries at peace towards countries at war.”[i] The law of neutrality as enshrined in the Hague Convention V Respecting the Rights and Duties of Neutral Powers and Persons in Case of War on Land [“Hague Convention V”] and the Hague Convention XIII Concerning the Rights and Duties of Neutral Powers in Naval War [“Hague Convention XIII”] lay down the formal rights and duties of neutral states during conflict.[ii] The duties of neutral states include abstention from participation in a war and impartiality in their dealings with belligerent states, and the rights of neutral states include protecting their territorial integrity from belligerent states, by force if necessary. The Hague Conventions explicitly permit neutral states to continue trading with belligerent states provided they refrain from selling munitions to the belligerents and impose equal trading restrictions (if any) upon each of the warring states.[iii]



The International Court of Justice’s Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons acknowledged the application of the law of neutrality to nuclear weapons.[iv] However, it did not go any further to delineate the scope of the application of the law of neutrality to nuclearization. Due to the peculiar nature of nuclear weapons and their inevitable consequence of lethal radioactive fallout that transcends territorial boundaries, the law of neutrality is practically rendered meaningless. The proponents of nuclear weapons as a mode of deterrence have argued that any harmful effect of the use of such weapons is merely collateral damage and does not per se violate the principle of neutrality.[v] A plain reading of Article I of the 1907 Hague Convention V, which states that the territory of a neutral state is inviolable, indicates that this provision is absolute and unconditional.[vi] Further, the deleterious and irreversible effects of radiation due to the use of nuclear weapons — ranging from injury and loss of life to environmental degradation and “nuclear winters” — qualifies radioactive fallout as an instrumentality of war.[vii] Thus, this means that any radioactive fallout or other blast effects of a nuclear weapon that are not intended for a neutral state but carry over into such a state’s territory and adversely affect its population would result in violation of the law of neutrality. 

Since nuclear weapons are unable to differentiate between belligerent and neutral states, the scope of the law of neutrality is limited.[viii] In order to be meaningful, the principle of neutrality has to emphasize complete avoidance of nuclear war due to the uncontrollable and adverse effects of the use of nuclear weapons.[ix] Even though the International Court of Justice in its Advisory Opinion was unable to hold the threat or use of nuclear weapons to be illegal when the existence of the state itself was threatened,[x] there has been a growing movement around the world to ban nuclear weapons altogether in light of the humanitarian consequences of such use. This has culminated in the Treaty for Prohibition of Nuclear Weapons that recently came into effect on 22 January 2021. This treaty prohibits state parties from using, threatening to use, developing, producing, manufacturing, acquiring, possessing, stockpiling, transferring, stationing, or installing nuclear weapons.[xi] This treaty aims to reinforce the objective of nuclear disarmament as already laid down in the Nuclear Non-Proliferation Treaty and the Comprehensive Test Ban Treaty. Even though none of the nine nuclear-equipped states have acceded to this treaty, it serves to delegitimize nuclear weapons and strengthen the position of illegality of their use, or threat to use, in international law. The obligation on states party to the Treaty for Prohibition of Nuclear Weapons is more pro-active as compared to the passive obligations under the Nuclear Non-Proliferation Treaty. While the latter urges states to undertake ‘negotiations’ in good faith for nuclear disarmament,[xii] the former calls upon states to play a more active role to eliminate any nuclear weapons programs of their own and remove any nuclear weapons belonging to another state from its territory.[xiii] It also imposes an obligation on nuclear powers who seek to accede to the treaty to either destroy its nuclear weapons and then accede to the treaty, or accede to the treaty and then destroy its nuclear weapons within 60 days of accession.[xiv]  

Thus, the law of neutrality has limited scope when applied to nuclear weapons. The nature of nuclear technology is such that if used it shall inevitably undermine the legitimate right of an independent state to remain neutral. Thus, only by avoiding nuclear war will states not party to the conflict be able to exercise their rights as neutrals and maintain their sovereignty. 


Article II of the 1967 Outer Space Treaty lays down that “the outer space including the moon and other celestial bodies is not subject to national appropriation by claims of sovereignty, by means of use or occupation or by any other means” and is reflective of customary international law.[xv] Thus, in space law, outer space is considered to be a res communis omnium, i.e. belonging to the entire community.[xvi] As the law of neutrality is strictly territorial in nature and outer space is exempt from any exercise of territorial sovereignty, this would imply that the law of neutrality does not apply to outer space. Due to this, it would be incorrect to apply the principle of neutrality under The Hague Convention V and The Hague Convention XIII to outer space as these provisions impose an obligation on belligerent parties to respect a neutral territory’s inviolability but do not extend to protect objects that are located outside this neutral territory. Thus, outer space is predominantly governed by space law and rules and principles of general international law. 

For instance, space objects used by a neutral state for non-commercial government purposes enjoy sovereign immunity that belligerent parties are bound to respect. This obligation to refrain from violating a neutral state’s sovereign immunity arises from general rules and principles of international law, such as the sovereign equality of states as laid down in Article 2 (1) of the United Nations Charter, and not necessarily from the law of neutrality.[xvii] Similarly, another branch of law that governs attacks against neutral space objects is the law of targeting. As per the law of targeting, if neutral space objects were to contribute in a belligerent party’s military action by virtue of their use, purpose, or location, then such neutral space objects can constitute lawful military objectives that can be attacked by the opposing belligerent party.[xviii] When a belligerent party attacks a neutral space object that offers a definite military advantage in consonance with the law of targeting, then the neutral state cannot plead violation of its sovereignty. 

Even though the law of neutrality is per se inapplicable to the outer space, this does not mean it is wholly irrelevant either. For instance, the launching of belligerent military space objects from within the territory of a neutral state amounts to a violation of the principle of neutrality. Additionally, the law of neutrality prohibits the incursion or transit of belligerent aircrafts, unmanned combat aerial vehicles, or missiles through neutral airspace.[xix] The scope of this prohibition also includes military space objects that transit neutral airspace before reaching outer space. In such cases, the neutral state must prevent or terminate such violation of its neutral airspace within its capability.[xx]

Further, the scope of Article III of The Hague Convention V as discussed above is broad enough to prohibit the erection, installation, and use of ground stations on neutral territory for controlling or communicating data to belligerent military space objects. As the belligerent party would effectively be using neutral territory as a base to conduct its military operations, such an act would be violative of the law of neutrality.[xxi]

Neutrality is also considered violated in the event that a neutral state supplies to a belligerent state any object that has military relevance, such as remote sensing satellite imagery or earth imaging data.  In this case, the supplying state would lose its neutral status.[xxii]

To conclude, even though the law of neutrality may not be applicable in outer space, it is still relevant to belligerent military space objects that are launched from neutral territory or transit through neutral airspace before reaching outer space. It is the duty of neutral states to exercise due diligence so as to prevent a satellite launch from their territory when they have reason to believe that such a satellite is intended for hostile operation against a belligerent party with which they are at peace.[xxiii]


Cyberspace is the interdependent network of information technology infrastructures that includes the internet, telecommunication networks, computer systems, and embedded processors and controllers in critical industries.[xxiv]Governments and industries all around the world are heavily dependent on cyberspace to store critical information and data, which renders this space more vulnerable to cyberattacks as a form of proxy conflict by belligerent parties. The 2007 attack on the Estonian government’s cyber infrastructure and the 2008 distributed denial of service (DDoS) cyberattack against Georgia, both allegedly by Russia, are two such instances. In the latter instance, Georgia sought cyber refuge in the servers of American private corporations without the approval of the U.S. government — a move that threatened the United States’ neutral status.[xxv]

The principle of neutrality is integral to cyber warfare. Given the internet’s borderless international structure, a belligerent may route the attack through neutral states’ servers or launch cyberattacks from within the territory of the neutral state itself. Even though there is no physical violation of the neutral state’s territory in such cases, attacks routed through their cyber infrastructure prima facie violate the principle of neutrality. As stated previously, the principle of neutrality is applicable in situations of international armed conflict. The position in international law as to whether cyberattacks constitute legitimate acts of armed conflict is unclear. The United Nations Charter defines an armed attack as a “crossing of geographic domains by the use of armed force.”[xxvi] In light of this, it has been argued that malicious software effectively moves a weapon across cyberspace that can cause physical destruction, and hence cyberattacks can constitute an armed attack within the meaning of the United Nations Charter.[xxvii] Thus, when an information packet containing a malicious code travels through the cyber infrastructure of a neutral state, it amounts to a ‘munition of war’ under Article II of The Hague Convention V and results in violation of such state’s neutrality.[xxviii]

The applicability of the principle of neutrality to cyberspace has also been reiterated in the HPCR Manual on International Law Applicable to Air and Missile Warfare, which has been endorsed by several states and hence evidences opinio juris.[xxix] In accordance with this principle, belligerent parties are prohibited from engaging in “the use of network-based capabilities to disrupt, deny, degrade, manipulate, or destroy information resident in computers and computer networks or the computers and networks themselves” of a neutral state.[xxx]

The principle of cyber neutrality confers upon a state not party to the cyber conflict the right to remain neutral by not taking sides or supporting any cyber belligerent so as to maintain relations with all belligerent parties. In addition to this, a strict interpretation of the concept of cyber neutrality also imposes a duty on neutral states to prevent a cyberattack from either originating or being routed through their cyber infrastructure, as well as preventing their own citizens from independently participating in a cyberattack in any way. This positive obligation on states poses practical problems for two reasons. First, it presupposes knowledge (either actual or constructive) of the neutral state before the cyberattack, which is highly improbable owing to the vastness of the cyber space. Second, it entails government surveillance of citizens’ activities within cyberspace through constant monitoring, which is unacceptable in most countries that protect citizens’ right to free speech/internet communication and privacy. Despite this, states may risk losing their neutral status if they fail to take action, which could entitle the belligerent party whose security interests have been adversely impacted to take measures to terminate the violation of neutrality.[xxxi]

Further, Article III of The Hague Convention V prohibits belligerents from erecting a wireless telegraphy station or any other apparatus for communicating with belligerent forces on land or sea within the territory of a neutral state.[xxxii] In the present context, the term ‘other apparatus’ has been interpreted broadly to include communication through cyberspace as well. In light of this, Georgia can be said to have violated this provision when it was a belligerent state in conflict with Russia and it set up websites in U.S. cyber neutral territory and used them to communicate with its forces. However, this law is subject to the exception laid down in Article VIII of The Hague Convention V that states that there is no violation of neutrality provided the neutral state impartially permits equal use of its telecommunications infrastructure to all belligerents.[xxxiii] Here, it is important to note that this exception applies only to telecommunications for military purpose but not to cyber weapons. 

Thus, it can be concluded that the traditional law of neutrality is applicable to cyberspace as well, and its special characteristics do not hinder such application. In order to prevent the escalation of an international armed conflict through belligerent cyber operations, it is of paramount importance that states arrive at a consensus regarding interoperability, network stability, reliable access and cybersecurity due diligence.[xxxiv]


Even though neutrality is an age-old concept that evolved with conventional warfare, its applicability to modern means of warfare still persists in varying degrees. Neutrality is rendered completely irrelevant in nuclear war due to the destructive nature of nuclear weapons that respects no borders. Further, the question of neutrality fails to arise in outer space, as such territory cannot be claimed by any state. However, neutrality is still relevant in the context of belligerent military space objects that are launched from neutral territory or transit through neutral airspace before reaching outer space. Lastly, with respect to cyberspace, the concept of neutrality is wholly applicable, provided cyberattacks are treated as legitimate acts of armed conflict — a position which requires further crystallization in international law. 


[i] Allen Dulles and Hamilton Armstrong, Can We Be Neutral? (New York: Harper and Brothers for Council on Foreign Relations, 1936), 196.

[ii] “Hague Convention (V) Respecting the Rights and Duties of Neutral Powers and Persons in Case of War on Land,” conclusion date: January 26, 1910, Hague International Peace Conference; “Hague Convention (XIII) Concerning the Rights and Duties of Neutral Powers in Naval War,” conclusion date: January 26, 1910, Hague International Peace Conference,

[iii] Hague Convention V, arts. 7, 9.

[iv] Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 1996 I.C.J. Rep. 226, ¶ 89 (1996),

[v] Scott Witthuhn, “The Law of Neutrality and the Threat or Use of Nuclear Weapons: Application of a Traditional Law to a Non-Traditional Weapon”, Fordham Lawyers Committee on Nuclear Policy (Fall 2011):

[vi] Hague Convention V, art. 1; Michael Bothe, “The Law of Neutrality,” in The Handbook of Humanitarian Law in Armed Conflicts, ed. Dieter Fleck (Oxford: Oxford University Press, 2013), 495. 

[vii] Witthuhn, “The Law of Neutrality and the Threat or Use of Nuclear Weapons,” 18. 

[viii] Memorial of the Government of the Republic of Nauru, Legality of the Threat or Use of Nuclear Weapons (Advisory Opinion), 1994 I.C.J. Pleadings 35 (Sep. 1995). 

[ix] Curt Dahlgren, “Neutrality, International Law and the Nuclear Arms Race,” in On Nuclear Weapons, Denuclearization, Demilitarization and Disarmament: Selected Writings of Richard Falk, ed. Stefan Andersson (Cambridge: Cambridge University Press, 2019), 167-182,

[x] Legality of the Threat or Use of Nuclear WeaponsAdvisory Opinion, 266. 

[xi] “Treaty on the Prohibition of Nuclear Weapons,” conclusion date: January 22, 2021, United Nations Treaty Series, registration no. 56487,, art. 1.

[xii] “Treaty on the Non-Proliferation of Nuclear Weapons,” opened for signature July 1, 1968, Treaty Series: Treaties and International Agreements Registered of Filed and Recorded with the Secretariat of the United Nations 729, no. 10485 (1974): 172,, art. 6. 

[xiii] Treaty on the Prohibition of Nuclear Weapons, art. 3.  

[xiv] Treaty on the Prohibition of Nuclear Weapons, art. 4. 

[xv] “Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies,” opened for signature January 27, 1967, United Nations Treaty Series 610: 205,

[xvi] Vladlen S. Vereshchetin, “Outer Space,” in Max Planck Encyclopedia of Public International Law, ed. R. Wolfrum (Oxford: Oxford University Press, 2006), ¶ 5. 

[xvii] “Charter of the United Nations,” opened for signature June 26, 1945, United Nations Treaty Series XVI, no. 1, , art. 2, ¶ 1. 

[xviii] Wolff Heintschel von Heinegg, “Neutrality and Outer Space,” Stockton Center for the Study of International Law 93, (2017):

[xix] Program on Humanitarian Policy and Conflict Research at Harvard University, Manual on International Law Applicable to Air and Missile Warfare (Cambridge: Cambridge University Press, 2013), r. 170 (a).

[xx] Ibid., r. 170 (c) 

[xxi] Louise Doswald-Beck, “San Remo Manual on International Law Applicable to Armed Conflicts at Sea,” American Journal of International Law 89, no. 1 (1995): 192-208.

[xxii] Heintschel von Heinegg, “Neutrality and Outer Space,” 541. 

[xxiii] Michel Bourbonnière, “The Ambit of the Law of Neutrality and Space Security,” in Israel Yearbook on Human Rights (Leiden: Martinus Nijhoff Publishers, 2006), 221.

[xxiv] National Security Presidential Directive 38/ Homeland Security Presidential Directive 23, Security and Monitoring (2008).

[xxv] Joshua E. Kastenberg, “Non-Intervention and Neutrality in Cyberspace: An Emerging Principle in the National Practice of International Law,” Air Force Law Review 64 (2009): 43.

[xxvi] Charter of the United Nations, art. 51. 

[xxvii] Davis Brown, “A Proposal for an International Convention to Regulate the Use of Information Systems in Armed Conflict,” Harvard International Law Journal 47, no.1 (Winter 2006): 179.

[xxviii] William J. Bayles, “The Ethics of Computer Network Attack,” Parameters: US Army War College Quarterly (Spring 2001): 44-45.

[xxix] Program on Humanitarian Policy and Conflict Research, Manual on International Law, sec. X.

[xxx] Arie J. Schaap, “Cyber Warfare Operations: Development and Use under International Law,” Air Force Law Review 64 (Winter 2009): 127.

[xxxi] Wolff Heintschel von Heinegg, “Neutrality in Cyber Space”, in 2012 4th International Conference on Cyber Conflict, ed. C. Czosseck (Tallinn: NATO Cooperative Cyber Defence Centre of Excellence, 2012)

[xxxii] Hague Convention V, art. 3. 

[xxxiii] Hague Convention V, art. 8. 

[xxxiv] The White House, International Strategy for Cyberspace: Prosperity, Security, Openness in a Networked World (Washington, 2011), 10,