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Prepared by: U.S. Indo-Pacific Command Office of the Staff Judge Advocate (J06) & U.S. Pacific Fleet Legal Office (N01J)

Last Updated: October 23, 2023 (all prior versions obsolete)

**This TACAID includes legal opinion and analysis that does not necessarily reflect official U.S. government positions.

USINDOPACOM J06/SJA TACAID SERIES

TOPIC: Naval Mine Warfare

BLUF

 Naval mines are lawful weapons, but use is subject to specific rules that minimize risk to neutral shipping.i

 Naval mining must comply with customary international law and the law of armed conflict in order to minimize 

the risk of harm to neutral vessels.ii

 States engaged in naval mining have an obligation to take feasible precautions to protect neutral vessels—

specifically, States must record the location of minefields, provide international notification as soon as military 

exigencies permit, actively monitor minefields to minimize harm to innocent shipping, and do their utmost to 

remove (or render harmless) naval mines post-conflict.iii

 Naval mines provide a low-cost battlespace shaping and force protection capability, and are especially useful for 

area denial, coastal and harbor defense, anti-surface and antisubmarine warfare, and blockade.

 Modern naval mines vary in their design and capabilities. Specific deployment and employment rules depend on 

the characteristics of the mine (i.e. armed or controllable) and the location of the minefield (i.e. internal waters, 

territorial sea, archipelagic waters, or waters beyond the territorial sea of any coastal State) as well as whether 

the mining occurs in peacetime or during armed conflict.

WHY THIS MATTERS 

 Naval mines are likely to remain relevant to modern joint operations because they represent a combination of 

military effectiveness with economical means to achieve maritime advantages.

 Significant technological advances have improved the precision of naval mines, but specific rules still apply to the 

use of mines to mitigate the risk posed to neutral vessels.

 Recent reports of the hazards of naval mines to merchant vessels in the Black Sea highlight the risks naval mines 

pose to neutral shipping and the importance of compliance with the specific rules for the use of naval mines.iv

 Russia and the People’s Republic of China (PRC) maintain significant stockpiles of legacy naval mines, and analysts 

contend that the PRC’s People’s Liberation Army could deploy such mines during conflict in the Taiwan Strait.”v

 Understanding naval mines and the rules associated with their use will enable military professionals to better plan

and execute naval operations, and may assist States as they seek to prioritize investments in lawful weapons.

DETAILED DISCUSSION

 Mines have been part of naval warfare for centuries, with the U.S. Navy first employing naval mines in the 

American Revolution.vi

 Due to the risk automatic contact mines pose to neutral shipping (and motivated by the significant damage to 

innocent shipping during and after the Russo-Japanese War of 1904-1905), the international community 

developed specific rules for the use of naval mines.vii

 These rules are contained in the Hague Convention of 1907 Relative to the Laying of Automatic Submarine Mines 

(Hague VIII), which remains the only document to codify rules specifically addressing the emplacement of 

conventional naval mines.

viii Hague VIII is focused on the use of naval mines during armed conflict.

o Hague VIII sought to protect sea routes (“the common highway of all nations”) by restricting and 

regulating employment of automatic contact mines (ACMs).

ix

1. History of Naval Mining 
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o Hague VIII forbids the laying of unanchored ACMs unless they “become harmless one hour at most after 

the person who laid them ceases to control them” (Art. 1).

o Hague VIII also forbids the laying of anchored ACMs unless they “become harmless as soon as they have 

broken loose from their moorings” (Art. 1).

o States may not lay ACMs “off the coast and ports of the enemy, with the sole object of intercepting 

commercial shipping” (Art. 2).

o States employing mines must take “every possible precaution” to protect neutral shipping, including

warning ship owners and other States of the presence of mines as soon as military exigencies permit and 

doing “their utmost” to render mines harmless within a limited time (Art. 3).

o Typically, States provide notice to ship owners via a notice to mariners (NOTMAR) or other navigational 

warning issued pursuant to the International Maritime Organization/International Hydrographic 

Organization World-Wide Navigational Warning Service (WWNWS).

x

 

o Feasible precautions may also include surveilling the minefield to reduce the risk of harm to neutral 

shipping.

o The rules for laying ACMs also apply to neutral States mining off their own coasts (Art. 4).

o At the conclusion of a conflict, State parties to Hague VIII are obligated “to do their utmost to remove 

mines which they have laid” (Art. 5).

o The PRC and the United States are State parties to Hague VIII; Russia is not. Nevertheless, Hague VIII is 

viewed as customary international law.

xi

 Modern naval mine technology has progressed significantly since Hague VIII, with some modern mines being able 

to precisely target, including arming or detonating based on 

acoustic/magnetic signatures or changes in water pressure 

caused by passing vessels.xii

o While Hague VIII did not contemplate these 

technological advancements, “the general principles 

of law embodied in [Hague VIII] continue to serve as a 

guide to lawful employment of naval mines.”xiii

 Today, the U.S. Navy categorizes mines as armed (“emplaced 

with all safety devices withdrawn or armed following 

emplacement, so as to detonate when preset parameters (if 

any) are satisfied”) or controllable (“no destructive capability 

until affirmatively activated by some form of arming order.”xiv

The U.S. Navy used naval mines extensively in World War II and throughout its history. Today, the U.S. Navy maintains two types of in-service mines, the 

Quickstrike mine (Marks 62, 63, and 65) and the Submarine Launched Mobile Mine (SLMM) (Mark 67), with several developmental programs active.

2. Modern Naval Mining 

U.S. forces conduct mine 

countermeasure training 

during a combined exercise 

with the Japan Maritime SelfDefense Force in July 2021. 

Image Source: INDOPACOM
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 The rules for the use of armed or controllable naval mines vary depending on (1) whether States are in 

peacetime or armed conflict and (2) the location to be mined.

o Peacetime Naval Mining: Naval mines may be lawfully employed by States during peacetime subject to 

the following restrictions:

 State’s Own Internal Waters. A State (taking into account the safety of its own citizenry) “may 

emplace armed and controllable mines in its own internal waters with or without notification.”

xv

 State’s Own Territorial Sea (TTS) and/or Archipelagic Waters (AW). A State “may mine its own

[TTS and/or AW] when deemed necessary for national security purposes” under certain 

conditions:

 Use of armed mines in a State’s own TTS and/or AW requires international notification of 

the existence and location of naval mines, and armed mines must be removed/render 

harmless as soon as the security threat has terminated.

 Use of controllable mines in a State’s own TTS and/or AW is not subject to notification or 

removal requirements.xvi

 International Straits or Archipelagic Sea Lanes. States may not emplace armed mines in 

international straits or archipelagic sea lanes during peacetime.xvii

 3

rd Party State’s Internal Waters, TTS, or AWs. A State may not emplace naval mines (both 

armed or controllable) in another State’s internal waters, TTS, or AW in peacetime without the 3rd

party State’s consent.xviii

 Waters Beyond the Territorial Sea of Any Coastal State (International Waters). 

 States may not emplace armed mines in international waters prior to armed conflict 

“except under the most demanding requirements of individual or collective self-defense.” 

If emplaced under such circumstances, States must provide prior notification of their 

location and maintain an on-scene presence in the area to warn approaching ships. 

States must expeditiously remove or render harmless armed mines once the imminent 

threat that prompted their emplacement has passed.xix

 States may emplace controllable mines in international waters (i.e. beyond the TTS) if 

they do not unreasonably interfere with other lawful uses of the oceans. Analysis of what 

constitutes unreasonable interference is based on the purpose for mining (i.e., selfdefense interests of emplacing State), the extent of area to be mined, hazards (if any) to 

other lawful ocean uses, and duration of emplacement. Controllable mines do not 

constitute a hazard to navigation, so there are no notification requirements associated 

with emplacement in international waters.xx

o Naval Mining During Armed Conflict: Naval mines may be lawfully employed by parties to an armed 

conflict subject to the following restrictions:

 “International notification of the location of emplaced mines must be made as soon as military 

exigencies permit [Hague VIII, Art. 3].

 Mines may not be emplaced by belligerents in neutral waters [neutral waters include the internal 

waters (ports), territorial sea, and archipelagic waters of any neutral State and do not include the 

contiguous zone, the exclusive economic zone, the continental shelf, or the high seas.]

xxi

 Anchored mines must become harmless as soon as they break from moorings [Hague VIII, Art. 1].

 Unanchored mines not otherwise be affixed or imbedded in the bottom (seabed) and must 

become harmless within one hour after loss of control over them [Hague VIII, Art. 1].

 The location of minefields must be carefully recorded to ensure accurate notification and 

facilitate subsequent removal and/or deactivation [Hague VIII, Arts. 3 and 5]. 

 Naval mines may be employed to channelize neutral shipping, but not in a manner to deny transit 

passage of international straits or archipelagic sea lanes passage by such shipping. 

3. Naval Mining During Peacetime & Armed Conflict
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 Naval mines may not be emplaced off the coasts and ports of the enemy with the sole objective 

of intercepting commercial shipping. They may otherwise be employed in the strategic blockade 

of enemy ports, coasts, and waterways. 

 It is prohibited to mine areas of indefinite extent in international waters. Reasonably limited 

barred areas may be established by naval mines provided neutral shipping retains an alternate 

route around or through such an area with reasonable assurance of safety.”

xxii

 Naval mining has taken on a prominent role in PLA doctrine and some analysts assess the PLA Navy “is already 

fully capable of blockading Taiwan and other crucial sea lines of communication in the western Pacific area.”xxiii

o The PRC maintains a substantial inventory of naval mines, with estimates of the PRC mine inventory 

ranging from 50,000 to 100,000 naval mines.

xxiv

o The PRC’s mine “order of battle” reportedly includes 

drifting or free-floating mines (i.e. unanchored 

ACMs), use of which could violate Hague VIII and the 

law of armed conflict if they do not become 

harmless one hour after ceasing to be controlled and 

if they are incapable of being directed at a specific 

military objective.

xxv

o The PRC has reportedly ceased development of 

unanchored ACMs and the “most recent known 

equivalent to a [PRC] operations-law handbook 

notes that [Hague VIII] restricts sea-mine use;” 

however, the PRC handbook adds the caveat that States undermined Hague VIII by their extensive use of 

non-compliant mines in World War II and “Chinese analysts conclude that national interests inevitably 

trump legal norms.”xxvi

o Recognizing that the PRC “official defense budget continues to grow and is about 17 times larger than 

Taiwan’s defense budget, with much of it focused on developing the capability to unify Taiwan with the 

PRC by force,” Taiwan has sought to increase its defense acquisitions to bolster its forces against PRC 

pressure, including in the area of mining and minesweeping.

xxvii

PROPOSED COUNTER-LAWFARE APPROACH

** This section offers suggested language for incorporation into communications strategies **

 Upholding international law and protecting a free and open ocean are interests for all nations. As fundamental 

pillars of the rules-based international order that benefits all nations, international law and free and open oceans 

are vital to global peace, security, and prosperity. 

 Use of naval mines is a valid means and method of naval warfare, but must comply with the law of armed 

conflict, including the need to take feasible precautions for the protection of civilians during a conflict and the 

obligation to remove mines at the conclusion of the conflict. All States must respect customary international law 

as reflected in Hague Convention VIII. 

 Naval mining represents a legitimate and effective military capability to defend against aggression. Whether 

used in competition, crisis or conflict, military commanders may lawfully employ naval mines to deter aggression 

or defeat an invading force. 

 USINDOPACOM supports and defends international law. USINDOPACOM seeks to preserve peace and stability, 

uphold freedom of the seas in a manner consistent with international law, maintain the unimpeded flow of 

commerce, and oppose any attempt to use coercion or force to settle disputes. USINDOPACOM shares these 

deep and abiding interests with our many allies and partners who champion a free and open Indo-Pacific 

supported by the rules-based international order.

4. Naval Mining by the PRC

PLA Navy conducts naval mining exercise in South China Sea in 2016. 

Source: http://en.people.cn/n3/2016/0827/c90000-9106322.html
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i Department of Defense Law of War Manual, June 2015 (updated July 2023), §13.11, available at 

https://media.defense.gov/2023/Jul/31/2003271432/-1/-1/0/DOD-LAW-OF-WAR-MANUAL-JUNE-2015-UPDATEDJULY%202023.PDF [hereinafter DoD LoW Manual]; NWP 1-14M/MCTP 11-01B/COMDTPUB P5800.7A, The Commander’s 

Handbook on the Law of Naval Operations, March 2022, §9.2, available at 

https://usnwc.libguides.com/ld.php?content_id=66281931 [hereinafter NWP 1-14M]; Newport Manual on the Law of 

Naval Warfare, 2023, §7.2.3, available at https://digitalcommons.usnwc.edu/cgi/viewcontent.cgi?article=3047&context=ils [hereinafter Newport Manual].

ii Id.

iii Newport Manual, supra note 1, §7.2.3.

iv See Raul (Pete) Pedrozo, “Dangerous Waters: Use of Naval Mines in the Russia-Ukraine Conflict,” 15 June 2022, 

Lawfire, https://sites.duke.edu/lawfire/2022/06/15/guest-post-prof-pete-pedrozo-on-dangerous-waters-use-of-navalmines-in-the-russia-ukraine-conflict/.

v

See e.g., Andrew S. Erickson, Lyle J. Goldstein, and William S. Murray, “Chinese Mine Warfare: A PLA Navy ‘Assassin’s 

Mace’ Capability,” China Maritime Studies, no. 3 (Newport, R.I: China Maritime Studies Institute, U.S. Naval War College, 

2009), 5, available at https://digital-commons.usnwc.edu/cgi/viewcontent.cgi?article=1002&context=cmsi-red-books

(“The moment conflict erupted in the Taiwan Strait, the [People’s Liberation Army (PLA)] Navy could deploy mines.”). 

vi “Naval Mine Warfare,” Naval History and Heritage Command, https://www.history.navy.mil/browse-bytopic/exploration-and-innovation/naval-mine-warfare.html; “US Navy Mines,” 8 October 2021, 

https://www.navy.mil/Resources/Fact-Files/Display-FactFiles/Article/2167942/us-navy-mines/. 

vii NWP 1-14M, supra note 1, at §9.2.

viii Id.

ix Convention Relative to the Laying of Automatic Submarine Contact Mines (Hague VIII), 18 October 1907, available at 

https://ihl-databases.icrc.org/en/ihl-treaties/hague-conv-viii-1907?activeTab=default. 

x

See Pedrozo, supra note iv.

xi Id. 

xii NWP 1-14M, supra note 1, at §9.2.1.

xiii Id. at §9.2.

xiv Id. at §9.2.1; see also DoD LoW Manual, supra note 1, at §13.11.1.

xv NWP 1-14M, supra note 1, at §9.2.2.

xvi Id.

xvii Id.

xviii Id.

xix Id.

xx Id.

xxi See DoD LoW Manual, supra note 1, at §15.7.1; Newport Manual, supra note 1, at §11.3.1.

xxii Id. at §9.2.3.

xxiii Erickson, Goldstein, and Murray, supra note v, at 2.

xxiv Id. at 11.

xxv Id.

xxvi Id. at 19.

xxvii Annual Report to Congress: Military and Security Developments Involving the People’s Republic of China 2022” 

(Office of the Secretary of Defense), 131, available at https://media.defense.gov/2022/Nov/29/2003122279/-1/-

1/1/2022-MILITARY-AND-SECURITY-DEVELOPMENTS-INVOLVING-THE-PEOPLES-REPUBLIC-OF-CHINA.PDF.