Rule 86. Blinding Laser Weapons
Rule 86. The use of laser weapons that are specifically designed, as their sole combat function or as one of their combat functions, to cause permanent blindness to unenhanced vision is prohibited.
Summary
State practice establishes this rule as a norm of customary international law applicable in both international and non-international armed conflicts. Blindness to unenhanced vision refers to blindness caused to the naked eye or to the eye with corrective eyesight devices.[1] 
International armed conflicts
Although the adoption of Protocol IV to the Convention on Certain Conventional Weapons governing the use of blinding laser weapons in 1995 is only recent, the circumstances of that adoption and developments since then indicate that this is an instance of customary international law developing as a result of the negotiation and adoption of a treaty. In its judgment in the North Sea Continental Shelf cases, the International Court of Justice stated that customary international law can develop in this way:
Although the passage of only a short period of time is not necessarily, or of itself, a bar to the formation of a new rule of customary international law on the basis of what was originally a purely conventional rule, an indispensable requirement would be that within the period in question, short though it might be, State practice, including that of States whose interests are specially affected, should have been both extensive and virtually uniform in the sense of the provision invoked; and should moreover have occurred in such a way as to show a general recognition that a rule of law or legal obligation is involved.[2] 
Prior to the negotiation of Protocol IV to the Convention on Certain Conventional Weapons, several States had laser weapons programmes that allegedly included the development of blinding anti-personnel laser weapons or dual-use laser weapons. According to a report by Human Rights Watch, China, France, Germany, Israel, Russia, Ukraine, the United Kingdom and the United States had such programmes.[3]  However, apart from the systems developed by China and the United States, it is not clear to what extent this report is accurate and, if so, which of the proposed systems would have fallen within the prohibition of Protocol IV. Nonetheless, it is clear that, with the exception of Sweden, States did not consider that such programmes were prohibited before the First Review Conference of the Convention on Certain Conventional Weapons.[4]  They began to consider the issue because of concerns raised by some States, the ICRC and non-governmental organizations which objected to deliberate blinding as a method of warfare.[5] 
Protocol IV to the Convention on Certain Conventional Weapons was adopted by consensus, with every State said to have been involved in the development of anti-personnel laser systems present at the conference. All the States mentioned in the Human Rights Watch report, with the exception of the United States, have become party to the Protocol. In the case of the United States, the Protocol mirrors the Pentagon’s policy, which was announced a few weeks before the adoption of the Protocol.[6]  The United States withdrew the anti-personnel lasers it was about to deploy, even though it was not party to Protocol IV.[7]  All major weapons-exporting States, with the exception of the United States, and the vast majority of other States capable of producing such weapons, have acceded to it. The fact that the Protocol also prohibits transfers means that non-party States will not be able to acquire the weapon unless they produce it themselves.[8]  At present, there is no indication that this is occurring.
Although the United States is not yet a party to Protocol IV, its Secretary of Defense stated in relation to blinding lasers that “the Department has no intent to spend money developing weapons we are prohibited from using”.[9]  China stated at the adoption of the Protocol that “this is the first time in human history that a kind of inhumane weapon is declared illegal and prohibited before it is actually used”.[10] 
Subsequent practice is universally consistent with the prohibition of using laser weapons contained in Protocol IV. There have been no reports that such weapons have been deployed or used by any State since the adoption of the Protocol. Government statements are consistent with this prohibition and none have expressed the belief that they are entitled to use such weapons.[11] 
Non-international armed conflicts
At the negotiations of Protocol IV to the Convention on Certain Conventional Weapons in 1995, all States were in favour of making the Protocol applicable to non-international armed conflicts, with the exception of one State. The objecting State was not in the process of developing or acquiring this weapon and the State’s representative indicated orally that while his government was in favour of totally banning such weapons, it would resist the adoption of a treaty on international humanitarian law applicable to non-international armed conflicts as a matter of principle, irrespective of the subject matter.[12]  Since then, however, this State agreed to the amendment of the Convention on Certain Conventional Weapons in 2001 to extend application of the Protocol also to non-international armed conflicts and the amendment has meanwhile entered into force.[13]  It is also noteworthy that the Protocol prohibits transfers to both States and non-State entities.[14] 
Practice is in conformity with the rule’s applicability in both international and non-international armed conflicts, as States generally do not have a different set of military weapons for international and non-international armed conflicts. There have been no reports of use or deployment in either international or non-international armed conflict. No State has claimed that it is entitled to use such systems in either international or non-international armed conflicts.
The Final Declaration adopted by consensus at the First Review Conference of the Convention on Certain Conventional Weapons in 1996 noted “the need for achieving the total prohibition of blinding laser weapons, the use and transfer of which are prohibited in Protocol IV”, thus reflecting the wish to achieve the elimination of such systems and not to limit the law to a prohibition of use and transfer.[15]  In the Final Declaration adopted at the Second Review Conference in 2001, States parties to the Convention solemnly declared “their reaffirmation of the recognition by the First Review Conference of the need for the total prohibition of blinding laser weapons, the use or transfer of which are prohibited in Protocol IV”.[16] 
The United States has indicated that it intends to apply the terms of Protocol IV in all circumstances, and a number of States specified, on declaring their intention to be bound by it, that they would not limit the Protocol’s application to situations of international armed conflict.[17]  It is not clear whether those States which adhered to the Protocol without making a statement as to its scope intended that scope to be limited or whether they simply did not consider it important to make such a statement. States have in practice totally abstained from the use of such weapons since the adoption of the Protocol, and it can reasonably be inferred that this is a reaction to the international community’s expectation that such weapons must not be used.
Some States consider that the use of blinding laser weapons would cause unnecessary suffering,[18]  an argument equally valid in international and non-international armed conflicts (see Rule 70).
Deliberate blinding by other laser systems
In addition to prohibiting the use and transfer of a certain type of laser weapon, Protocol IV to the Convention on Certain Conventional Weapons has the effect of prohibiting the deliberate use of other laser systems (for example, range-finders) to blind combatants.[19]  The deliberate use of laser systems, other than those prohibited by Protocol IV, to blind combatants would frustrate the aim and purpose of the prohibition of laser weapons that are specifically designed to cause permanent blindness. There is no evidence of deliberate use of other laser systems to blind combatants and no State has claimed the right to do so since the adoption of Protocol IV.
It is noteworthy that during the negotiations leading to the adoption of Protocol IV in 1995, a number of States, including some not yet party to Protocol IV, stated that they would have preferred a stronger text that included a prohibition of blinding as a method of warfare.[20]  This was resisted by a few States during the negotiations on the basis that weapons which are not laser weapons can sometimes have the effect of blinding, for example, bomb fragments, and that laser target designators may also have this effect although this would be unintended. However, these States did not suggest that the deliberate use of a weapon to blind would therefore be lawful, but, on the contrary, accepted the inclusion of the requirement to take feasible precautions in the employment of laser systems to avoid permanent blindness contained in Article 2 of Protocol IV.[21]  This requirement is set forth in military manuals and official statements, including those of States not, or not at the time, party to Protocol IV.[22] 

[1] Protocol IV to the Convention on Certain Conventional Weapons, Article 1 (cited in Vol. II, Ch. 31, § 1).
[2] ICJ, North Sea Continental Shelf cases, Judgment, 20 February 1969, ICJ Reports 1969, p. 44, § 74; see also supra, Introduction.
[3] Human Rights Watch Arms Project, Blinding Laser Weapons: The Need to Ban a Cruel and Inhumane Weapon (cited in Vol. II, Ch. 31, § 83).
[4] See the statements of Sweden (ibid., §§ 39–45).
[5] See, e.g., the statements of France (ibid., § 30), Germany (ibid., §§ 31–32), Ireland (ibid., § 35), Netherlands (ibid., § 38), Sweden (ibid., §§ 39–45), Switzerland (ibid., § 40) and USSR (ibid., § 46), the statements and practice of the ICRC (ibid., §§ 76–78) and the statements of several non-governmental organizations (ibid., §§ 85–90).
[6] United States, Announcement by the Secretary of Defense (ibid., § 48).
[7] See the practice of the United States (ibid., §§ 48–50).
[8] Protocol IV to the Convention on Certain Conventional Weapons, Article 1 (ibid., § 1).
[9] United States, Letter from the Secretary of Defense to Senator Patrick Leahy (ibid., § 49).
[10] China, Statement at the First Review Conference of States Parties to the Convention on Certain Conventional Weapons (ibid., § 29).
[11] See, e.g., the statements of Australia (ibid., § 26), Burkina Faso (ibid., § 27), China (ibid., § 29), United Kingdom (ibid., § 47) and United States (ibid., §§ 49 and 51–53).
[12] See the practice (ibid., § 71).
[13] CCW, amended Article 1 (ibid., § 12). The amendment entered into force on 18 May 2004. To date 29, States have ratified the amended Convention on Certain Conventional Weapons: Argentina, Australia, Austria, Belgium, Bulgaria, Burkina Faso, Canada, China, Croatia, Estonia, Finland, France, Holy See, Hungary, Japan, Latvia, Liechtenstein, Lithuania, Mexico, Netherlands, Norway, Republic of Korea, Romania, Serbia and Montenegro, Slovakia, Spain, Sweden, Switzerland and United Kingdom.
[14] Protocol IV to the Convention on Certain Conventional Weapons, Article 1 (ibid., § 1).
[15] First Review Conference of States Parties to the Convention on Certain Conventional Weapons, Final Declaration (ibid., § 73).
[16] Second Review Conference of States Parties to the Convention on Certain Conventional Weapons, Final Declaration (ibid., § 74).
[17] United States, Statement at the First Review Conference of States Parties to the Convention on Certain Conventional Weapons (ibid., § 51) and Message from the President transmitting the Protocols to the Convention on Certain Conventional Weapons to the Senate for consent to ratification (ibid., § 53); Declarations made upon acceptance of Protocol IV by Australia (ibid., § 5), Austria (ibid., § 4), Belgium (ibid., § 4), Canada (ibid., § 4), Germany (ibid., § 6), Greece (ibid., § 4), Ireland (ibid., § 4), Israel (ibid., § 7), Italy (ibid., § 4), Liechtenstein (ibid., § 4), Netherlands (ibid., § 8), South Africa (ibid., § 4), Sweden (ibid., § 9), Switzerland (ibid., § 10) and United Kingdom (ibid., § 11).
[18] See, e.g., Sweden, Declaration made upon acceptance of Protocol IV to the Convention on Certain Conventional Weapons (cited in Vol. II, Ch. 20, § 14) and the military manuals of France (ibid., §§ 55–56).
[19] Protocol IV to the Convention on Certain Conventional Weapons, Article 2 (cited in Vol. II, Ch. 31, § 91).
[20] See the statements of Australia, Austria, Belgium, Denmark, Ecuador, Finland, France, Germany, Iran, Mexico, Netherlands, Norway, Poland, Romania, Russian Federation and Sweden (ibid., § 3). Iran and Poland are not party to Protocol IV.
[21] Protocol IV to the Convention on Certain Conventional Weapons, Article 2 (ibid., § 91).
[22] See Israel, Manual on the Laws of War (ibid., § 94); United Kingdom, Letter from the Secretary of Defence to the ICRC President (ibid., § 99); United States, Annotated Supplement to the Naval Handbook (ibid., § 95); Defenselink News Release (ibid., § 100).