International Law Studies 2014
Modern Maritime Neutrality Law
ike Mark Twain, rumors of the law of neutrality’s demise are an exag-
The rumors surfaced forcefully after the U.N. Charter was
adopted in 1945. There are still those who occasionally perpetrate them.
Yet national law of armed conflict manuals and several recent non-State
manuals rely heavily on traditional maritime neutrality law. It has particular
contemporary relevance as the U.S. pivots to the maritime Asia-Pacific, and
is no less relevant to European States, which remain reliant on critical sea
lines of communication through the Arabian Gulf, Red Sea and the Medi-
terranean. Principles of neutrality law are also asserted in relatively new are-
as of legal regulation, such as air and missile operations and cyber warfare.
Neutrality’s traditional “mustiness” has been superseded by a new vibrancy,
* Lieutenant Commander James Farrant, Barrister UK Royal Navy, is a faculty mem-
ber at the St ockton Center for the Study of International Law in the U.S. Naval War Co l-
lege. The views expressed in this article are those of the author and do not necessarily
represent the views of the UK Ministry of Defence or the UK government.
. Frank M. White, Mark Twain Amused, NEW YORK JOURNAL (June 2, 1897) (quoting
Mark Twain “The report of my death was an exaggeration” following the publ ication of
newspaper reports that he had died).
. See, e.g., Kevin J. Heller, The Law of Neutrality Does Not Apply to the Conflict with Al-
Qaeda and It’s a Good Thing, Too: A Response to Chang, 47 TEXAS INTERNATIONAL LAW
JOURNAL 115, 136 (2011).
. See PROGRAM ON HUMANITARIAN POLICY AND CONFLICT RESEARCH, COMMEN-
TARY ON THE HPCR MANUAL ON INTERNATIONAL LAW APPLICABLE TO AIR AND MIS-
SILE WARFARE (2009) [hereinafter AMW MANUAL]; TALLINN MANUAL ON THE INTER-
NATIONAL LAW APPLICABLE TO CYBER WARFARE (Michael N. Schmitt ed., 2013).
Modern Maritime Neutrality Law Vol. 90
which makes a detailed understanding of the rules and the principles they
defend ever more important.
Commentators have long observed that the law of maritime neutrality
has rarely been settled: not only were the rules alleged to be musty, but also
The most recent significant treaties governing neutrality law,
Hague Convention V Respecting the Rights and Duties of Neutral Powers
and Persons in Case of War on Land (Hague V)
and Hague Convention
XIII Concerning the Rights and Duties of Neutral Powers in Naval War
were agreed in 1907. The latter Convention, in particular,
was a far from comprehensive statement of the law. It included no provi-
sions on the law of blockade, contraband, prize law or belligerent visit and
search rights. This was a consequence of irremediable disagreement be-
tween States at the Second Hague Peace Conference.
A more detailed at-
tempt at codification of the law of naval warfare and maritime neutrality
was made at the London Conference of 1909. The resulting Declaration of
London was intended to be a code for application in an international prize
court. Looming war in Europe and hostility to the Declaration in, ironical-
ly, London meant that it would never be ratified and the international prize
court never became a reality.
Throughout this article, the law up to the
1909 Declaration of London will be referred to as the traditional law.
Before examining the substantive rules of maritime neutrality, this In-
troduction must set some parameters. It therefore briefly defines the three
broad principles of neutrality law, which inform the substantive rules of
maritime neutrality. Next, it assesses when and to whom the law of neutrality
applies. The Introduction then describes some of the sources relied upon
throughout this article.
. Detlev F. Vagts, The Traditional Concept of Neutrality in a Changing Environment, 14
AMERICAN UNIVERSITY INTERNATIONAL LAW REVIEW 83, 84 (1998) (“neutrality has a
slightly musty quality”).
. See 2 L. OPPENHEIM, INTERNATIONAL LAW: A TREATISE 383–99 (Ronald Rox-
burgh ed., 3d ed. 1921) [hereinafter OPPENHEIM VOL. II].
. Convention No. V Respecting the Rights and Duties of Neutral Powers and Pe r-
sons in Case of War on Land, Oct. 18, 1907, 36 Stat. 2310 [hereinafter Hague V].
. Convention No. XI II Concerning the Rights and Duties of Neutral Powers in Na-
val War, Oct. 18, 1907, 36 Stat. 2415 [hereinafter Hague XIII].
. See, e.g., the remarks of Mr. Martens on September 24, 1907 in respect of contra-
band. 3 THE PROCEEDINGS OF THE HAGUE PEACE CONFERENCES 1111 (James B. Scott
ed., 1921) [hereinafter HAGUE PROCEEDINGS VOL. III].
. STEPHEN C. NEFF, THE RIGHTS AND DUTIES OF NEUTRALS—A GENERAL HIS-
TORY 141–42 (2000).
International Law Studies 2014
Given how much has changed in the 105 years since the Declaration of
London was drafted, it is perhaps surprising that the three broad principles
which underpinned its provisions governing the conduct of neutrals are
still reflected in modern military manuals. First, as between belligerent and
neutral States, prima facie, the law of peace is applicable.
Second and third,
the interrelated principles of impartiality and abstention guide the neutral’s
conduct towards the belligerents. The duty of impartiality is one more of
form than substance. In the context of trade, for example: “‘Cash and car-
ry’ policies are legitimate even if one of the warring powers cannot get to-
gether the cash or is prevented by geography from doing any carrying.”
The duty of abstention requires neutral States not to involve themselves in
the hostilities. When resort to war was a question of policy unfettered by
legal restraint, this duty made little sense because the neutral State always
had the right to “throw up neutrality” and join the war.
However, it is
unquestionably a relevant duty since the establishment of the prohibition
on the use of force.
This prohibition, widely recognized as jus cogens, for-
bids a neutral State from abandoning neutrality and joining the conflict.
Accordingly, the duty of abstention is arguably stronger now than it was in
While the U.N. Charter reinforces the neutral duty of abstention, other
rights and duties of neutral States may be displaced if the Security Council
takes action under Chapter VII. Article 25 requires Member States to ac-
cept and carry out Security Council decisions. Article 103 provides that
where there is a conflict between a State’s Charter obligations and its obli-
gations under any other international agreement its Charter obligations
During the First Gulf War in 1991, Switzerland felt compelled to
take part in economic sanctions against Iraq, even though not yet a mem-
ber of the U.N. and officially neutral.
Should the Security Council make a
determination under Article 39 that an act of aggression by one State
. Committee on Maritime Neutrality, International Law Association, Helsinki Princi-
ples on the Law of Maritime Neutrality
in 68 INTERNATIONAL LAW ASSOCIATION REPORT OF
THE 68TH CONFERENCE, TAIPEI, 1998, at 496, princ. 1.3 (1998) [hereinafter Helsinki Prin-
. Vagts, supra note 4, 93 (1998).
. OPPENHEIM VOL. II, supra note 5, at 421.
. U.N. Charter art. 2(4).
. Id., art. 103.
. Dietrich Schindler, N eutrality and Morality: Developments in Switzerland and in the Inter-
national Community, 14 AMERICAN UNIVERSITY INTERNATIONAL LAW REVIEW 155, 162