The Status of the U.S. Coast Guard’s People, Bases and Equipment, and Vessels Under LOAC
The U.S. Naval Institute (USNI) recently published an article highlighting the integral role the U.S. Coast Guard might play in a future high-intensity conflict. Set in the context of the American Sea Power Project’s fictional War of 2026 scenario, wherein the United States is in armed conflict with China over Taiwan, the USNI article argued the “Coast Guard would lead in countering China’s efforts to degrade the United States’ ability to sustain the war at home.” This assertion is not unprecedented. Since its creation, the Coast Guard has supported numerous combat operations at home and overseas (e.g., First World War, Second World War, Operation Iraqi Freedom).
However, in a time when technology has increased the ability to deliver combat effects across vast distances at unprecedented speed, near-peer adversaries present novel threats to the U.S. homeland that did not exist before. Thus, consideration of the Coast Guard’s role in future wartime defense operations while simultaneously maintaining its peacetime regulatory and law enforcement missions, must account for the Coast Guard’s legal status during armed conflict. For instance, in an international armed conflict (IAC) (i.e., the fictional War of 2026 scenario), is a U.S. Coast Guard cutter conducting an ice-breaking patrol on the Great Lakes a lawful target?
In this post, we explore the question of the Coast Guard’s legal status, as well as its implications under the law of armed conflict (LOAC), with an emphasis on targetability. To do this, we first provide an overview of the Coast Guard and its status under domestic law as a multi-mission federal agency. Next, we survey the applicable international law concerning the status of the Coast Guard’s people, bases and equipment, and vessels during armed conflict. We conclude that, generally, the Coast Guard’s people and objects—not only those involved in frontline defense operations—are subject to attack, just as any other branch of the U.S. armed forces.
The Coast Guard’s Mission and Authorities
The Coast Guard is a federal agency within the U.S. Department of Homeland Security tasked with promoting safety and security in the maritime domain. Accordingly, the Coast Guard has a correspondingly extensive mission set, which requires the organization to be purposefully multidimensional and function as a law enforcement organization, regulatory agency, maritime first responder, member of the intelligence community, as well as a military service and member of the armed forces of the United States (see 14 United States Code (U.S.C.) §§ 101, 102, 103; and 10 U.S.C. § 101(a)(4)).
The employment of the Coast Guard as a multi-functional organization with both a civil and military purpose is woven throughout the organization’s history, reaching back to the establishment of the Revenue Cutter Service in 1790 (on this issue more broadly, see here, p. 14–17). Initial congressional authorizations allowed the Coast Guard to “cooperate” with the Navy at the direction of the President in times of war and conflict (see Act of March 2, 1799).
In 1915, the statutory language governing the Coast Guard’s military status became more defined, noting that the Coast Guard “shall constitute a part of the military forces of the United States and … shall operate under the Treasury Department in time of peace and operate as part of the Navy, subject to the orders of the Secretary of the Navy in time of war or when the President shall so direct.” Eventually, in 1949, Congress passed 14 U.S.C. § 101, reshaping the Coast Guard “as a military service and branch of the armed forces at all times.” This language remains unchanged to this day. In adding the phrase “at all times,” Congress not only captured the Coast Guard’s evolution as a military service but also reflected the gradual embrace of its perpetual military function with an increased mission set in defense operations.
Early statutory language implicitly tied the Coast Guard’s armed forces status to whether the organization had been shifted to the Navy in times of war. Today, however, 14 U.S.C. § 101 and 10 U.S.C. § 101(a)(4) secure the Coast Guard’s status as an armed force regardless of whether it is operating under the Department of Homeland Security or the Department of the Navy. Though transfer remains an option, it has not occurred since the Second World War (see here). Yet the Coast Guard has executed defense missions as an armed force both in peacetime and conflict (e.g., Vietnam, Korea, and Iraq).
Given the Coast Guard’s unique mission and authorities, we next survey the international law applicable to determining its legal status during armed conflict.
Applicable Law
As a preliminary matter, LOAC recognizes “that the population of an enemy state is generally divided into two classes: the armed forces and the civilian population, also sometimes called, respectively, ‘combatants’ and ‘civilians’” (U.S. Department of Defense (DoD), Law of War Manual, § 4.2). This bifurcation reflects the customary law principle of distinction. The 1977 Additional Protocol I (AP I) to the Geneva Conventions codifies distinction in Article 48. It states, “To ensure respect for and protection of the civilian population and civilian objects, the Parties to the conflict shall at all times distinguish between the civilian population and combatants and between civilian objects and military objectives and accordingly shall direct their operations only against military objectives.”
The definition employs the term “military objectives” as encompassing both persons (i.e., combatants or civilians directly participating in hostilities) and objects (International Committee of the Red Cross (ICRC) Commentary, art. 48; DoD, Law of War Manual, § 5.6.1). The United States, which is not a party to AP I, characterizes Article 48 as an accurate restatement of customary law (DoD Law of War Manual, §§ 2.5, 5.5; ICRC, Customary International Humanitarian Law study, rule 1).
Coast Guard People
The term “combatant” refers to three categories of persons: (1) members of the armed forces (except medical and religious personnel); (2) members of militias or volunteer corps that “belong to” a party to the conflict that meets certain criteria; and (3) members of a levée en masse (see AP I, art. 43; ICRC, Commentary, art. 43; DoD, Law of War Manual, § 4.3.3). AP I defines “armed forces” as consisting of “all organized armed forces, groups, and units” that subordinate themselves to the command of a party to an armed conflict (art. 43(1)). Like Article 48, Article 43 also articulates widely accepted customary law (see ICRC, Customary International Humanitarian Law study, rule 3, rule 4; DoD, Law of War Manual, § 4.3.3).
The United States, through 14 U.S.C. § 101 and 10 U.S.C. § 101(a)(4), has unequivocally—and intentionally—established its Coast Guard personnel as members of the armed forces. The Coast Guard’s mission, in part, as a law enforcement agency does not deprive it of its armed forces status. As expressly noted in the DoD Law of War Manual, “[t]he U.S. armed forces also include the Coast Guard,” despite normally operating under the Department of Homeland Security (§ 4.5.1).
Furthermore, under LOAC, when a State formally incorporates a law enforcement organization into its armed forces (i.e., through domestic legislation as the United States has done) its members receive combatant status “by virtue of their membership in the armed forces” regardless of their operational activities (see DoD, Law of War Manual, § 4.23; ICRC, Customary International Humanitarian Law study, rule 4, State practice). Thus, as members of an armed force, members of the Coast Guard are “at all times” combatants during an IAC unless otherwise protected (i.e., hors de combat).
Accordingly, Coast Guard members maintain the associated rights (i.e., lawful belligerents, prisoner of war status, and combatant immunity), duties (i.e., comply with LOAC), and liabilities (i.e., subject to attack) associated with their status. Unless hors de combat, “combatants may be attacked based solely on their status” (Schmitt and Widmar, On Target, p. 385; DoD, Law of War Manual, §§ 5.6.2, 5.7.1).
Although there are several exceptions to this rule (i.e., it is unlawful to attack combatants who are shipwrecked at sea), generally, the extent of the combatant’s “involvement in the hostilities is irrelevant” (On Target, p. 385). The DoD Law of War Manual makes this point clear, explaining that “combatants who are standing in a mess line, engaging in recreational activities, or sleeping remain the lawful object of attack” (§ 5.7.1). Accordingly, during an IAC to which the United States is a party, Coast Guard members, regardless of their duties, are lawful targets subject to the broader rules of targeting. Therefore, whether on board a U.S. naval ship conducting counter-piracy operations in the Arabian Sea, participating in domestic fisheries enforcement off the coast of Maine, or anything in between, Coast Guard members are equally as targetable under LOAC as their counterparts from the Army, Air Force, Navy, Marine Corps, and Space Force.
Coast Guard Bases and Equipment
Like the Coast Guard’s people, Coast Guard bases and equipment are also, generally, valid military objectives and liable to attack subject to the law of targeting. Military objectives include “any object which by its nature, location, purpose or use makes an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage” (DoD, Law of War Manual, § 5.6.3; AP I, art. 52(2); ICRC Customary International Humanitarian Law study, rule 8).
Relevant here, “nature” refers, in part, to objects that inherently contribute to military action (DoD, Law of War Manual, § 5.6.6.1; see also On Target, p. 392). Military bases and equipment, by their nature, contribute to military action and are, per se, always considered military objectives unless otherwise protected (e.g., medical facilities and transport) (DoD, Law of War Manual, § 5.6.4). This is the case regardless of whether the military base, for instance, is used for “training, billeting, or staging, or offensive or defensive purposes” (DoD, Law of War Manual, § 5.6.4.1). Thus, any Coast Guard small boat station, air station, or training center is generally targetable by enemy combatants subject to the law of targeting (i.e., the obligation to take precautions in attack and comply with the rule of proportionality).
Coast Guard Vessels and the Law of Naval Warfare
While Coast Guard bases and equipment are generally considered military objectives, a specific type of Coast Guard equipment—vessels—requires further analysis under the law of naval warfare. Similar to the law applicable to land warfare, “the law of naval warfare has sought to classify enemy vessels to protect those that are civilian or non-combatant in character” (DoD, Law of War Manual, § 13.3.2; U.S. Naval War College, The Commander’s Handbook on the Law of Naval Operations (NWP 1-14M), § 8.6). Here, we provide an analysis of the applicable law relevant to the three general categories of vessels within the Coast Guard’s fleet: (1) warships; (2) small crafts; and (3) coastal rescue craft.
A warship is:
[A] ship belonging to the armed forces of a State bearing the external marks distinguishing such ships of its nationality, under the command of an officer duly commissioned by the government of the State and whose name appears in the appropriate service list or its equivalent and manned by a crew that is under regular armed forces discipline (1982 UN Convention on the Law of the Sea (UNCLOS), art. 29; see also Newport Manual on the Law of Naval Warfare (Newport Manual), § 3.2.1; The Commander’s Handbook on the Law of Naval Operations (NWP 1-14M)).
As an armed force with commissioned officers, the Coast Guard has vessels that are considered warships. These vessels, called “cutters,” are 65 feet long or more, with accommodations for a crew to live aboard (see NWP 1-14M, § 2.2.1: “U.S. Coast Guard vessels designated USCGC [U.S. Coast Guard Cutter] under the command of a commissioned officer are warships under international law”). Coast Guard cutters vary in design and purpose and include vessels such as Icebreakers (i.e., Polar & Great Lakes), National Security Cutters, Bouy Tenders (i.e., Seagoing, Coastal, Inland, and River), and Patrol Boats, among others.
While many Coast Guard vessels unequivocally meet the plain language of the definition, some Coast Guard cutters are notably commanded by non-commissioned warrant and senior petty officers. However, this nuance does not necessarily remove the vessel’s warship designation, as international law leaves room for States to interpret “duly commission” broadly to include a wide spectrum of national expression including, for instance, placing a non-commissioned officer in command of a vessel that would otherwise meet the definition of a warship (see UNCLOS, Commentary, vol. II, art. 29.8(b)). Thus, at a minimum, some Coast Guard cutters (i.e., those cutters commanded by an officer), and arguably all Coast Guard cutters (i.e., also those commanded by non-commissioned officers), are warships as a matter of international law and possess the associated rights and liabilities of this status.
Regarding liabilities, warships are—by their nature—considered valid military objectives, per se, and liable to attack, destruction, or capture outside neutral territory, even if unarmed. This is true regardless of the vessel’s operational activity (DoD, Law of War Manual, § 13.3.2; NWP 1-14M, § 8.6.1; Newport Manual, §§ 3.1, 3.2.1). For instance, during an IAC, the U.S. Coast Guard cutter Mackinaw conducting an ice-breaking patrol on the U.S. side of the Great Lakes is liable to attack, destruction, or capture, even when simply conducting its routine waterways management operations.
On the other hand, warships are also entitled to belligerent rights including the right to conduct hostilities (i.e., blockade), to visit, search, and divert enemy and neutral vessels, and the right of capture (Newport Manual, § 3.1). Consequently, in this same scenario, the Mackinaw could also lawfully attack enemy military objectives regardless of its assignment as an ice-breaking patrol vessel. As an example of a Coast Guard warship exercising its belligerent rights, the Coast Guard cutter Sherman, in 1970, famously became “the last active U.S. warship to have sunk an enemy ship in battle.”
In addition to warships, the Coast Guard also has military small craft vessels. “Small craft” means a military watercraft “deployed from larger surface ships and submarine host platforms or launched from land” (Newport Manual, § 3.2.3; NWP 1-14M, § 2.3.3). The Newport Manual provides examples of small craft, including “rigid hull inflatable boats, landing craft air cushion, motor whaleboats, small/medium unmanned surface vessels and unmanned underwater vessels, and other small boats, craft, and vehicles deployed from larger vessels” (Newport Manual, § 3.2.3). The Coast Guard’s fourteen-foot to 38-foot cutter-based boats, which are deployed from cutters, and 45-foot and 25-foot response boats (RB-M/RB-S), which are deployed from land, are examples of boats within the Coast Guard’s small craft fleet.
Like warships, military small craft are considered valid military objectives unless otherwise protected. Small craft that are attached to and launched from a warship are considered an extension of that warship and, therefore, entitled to the same rights and liabilities (Newport Manual, § 3.2.3). Other military small craft, though not considered warships, are still targetable as valid military objectives based on their nature (see Coast Guard Bases and Equipment above) and “can be employed in belligerent operations” (Newport Manual, § 3.2.3). Thus, during armed conflict, the Coast Guard’s cutter-based boats and RB-M/RB-S are lawful targets irrespective of their individual operational activities (i.e., law enforcement, security, and/or boating safety operations).
Some vessels, regardless of their warship or small craft designation, are “specially protected because of the humanitarian functions they perform in the time of armed conflict” (Newport Manual, § 10.4). Under the law of naval warfare, protected vessels include hospital ships, medical transport ships, and, relevant here, “coastal rescue craft” (see 1949 Geneva Convention II (GC II), art. 27; Newport Manual, § 10.4). Coastal rescue craft are “small craft employed by the State or by the officially recognized lifeboat institutions for coastal rescue operations” (GC II, art. 27).
The Newport Manual further clarifies this definition, noting that State practice extends this special protection to vessels used by coast guards or search-and-rescue organizations under certain conditions including, in part, operation by a party to an IAC that “afford[s] relief and assistance to the wounded, sick and shipwrecked without distinction of nationality” (GC II, art. 30; see Newport Manual, §§ 10.4.3.1.1, 10.4.3.1.3). As a State-designated maritime search and rescue organization, the Coast Guard maintains and operates vessels that meet the categorical description of coastal search and rescue vessels. For example, the Coast Guard’s 47-foot motor lifeboat is designated for maritime search and rescue (see The Cutters, Boats, and Aircraft of the U.S. Coast Guard, p. 146). To qualify for special protection status in an IAC, however, the Coast Guard would have to comply with the requirements of GC II (i.e., limit the operational scope of the vessel to only search and rescue missions, ensure availability to aid without distinction of nationality, etc.).
Coastal rescue craft (and their installations) are afforded special protections. Specifically, they “must be neither captured nor attacked, and they must be allowed to perform coastal rescue operations” (Newport Manual, § 10.4.3.1.2). Like all protected vessels, a coastal rescue craft can lose its protected status if it fails to meet the conditions required by GC II, and can become liable to attack if they commit acts harmful to the enemy (Newport Manual, § 10.4.3.1.4). Consequently, if the Coast Guard’s 47-foot motor lifeboat referenced above was used to transport ammunition to a Coast Guard warship, it would lose any protections afforded under this coastal rescue craft exemption.
Concluding Thoughts
During an IAC, members of the Coast Guard, its bases and equipment, and its vessels, are subject to attack just as any other branch of the U.S. armed forces. Thus, in a potential future conflict in which the Coast Guard will play a critical role in homeland defense, it is imperative that the joint force understand the rights, duties, and—most importantly—liabilities of the Coast Guard’s people and objects during the planning and execution of military operations. Further, an increased role in the United States’ broader war effort means that attacking Coast Guard units would inherently present a greater military advantage to the enemy. The Coast Guard and the joint force must be ready.
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Major Alex Hernandez is an active-duty Army judge advocate and a military professor assigned to the Stockton Center for International Law in Newport, Rhode Island.
Commander Liz Hutton is an active-duty Coast Guard Judge Advocate and military professor in the Stockton Center for International Law.
Photo credit: Julian Colton
