TREATY ON THE PROHIBITION OF THE EMPLACEMENT OF NUCLEAR
WEAPONS AND OTHER WEAPONS OF MASS DESTRUCTION ON THE SEABED
AND THE OCEAN FLOOR AND IN THE SUBSOIL THEREOF
Like the Antarctic Treaty, the Outer Space Treaty, and the Latin American Nuclear-Free Zone,
the Seabed Treaty sought to prevent the introduction of international conflict and nuclear
weapons into an area hitherto free of them. Reaching agreement on the seabed, however,
involved problems not met in framing the other two agreements.
In the 1960s, advances in the technology of oceanography and greatly increased interest in the
vast and virtually untapped resources of the ocean floor led to concern that the absence of clearly
established rules of law might lead to strife. And there were concurrent fears that nations might
use the seabed as a new environment for military installations, including those capable of
launching nuclear weapons.
In keeping with a proposal submitted to the U.N. Secretary General by Ambassador Pardo of
Malta in August 1967, the U.N. General Assembly, on December 18, 1967, established an ad hoc
committee to study ways of reserving the seabed for peaceful purposes, with the objective of
ensuring "that the exploration and use of the seabed and the ocean floor should be conducted in
accordance with the principles and purposes of the Charter of the United Nations, in the interests
of maintaining international peace and security and for the benefit of all mankind." The
Committee was given permanent status the following year. At the same time, seabed-related
military and arms control issues were referred to the ENDC and its successor, the CCD.1 In a
message of March 18, 1969, President Nixon said the American delegation to the ENDC should
seek discussion of the factors necessary for an international agreement prohibiting the
emplacement of weapons of mass destruction on the seabed and ocean floor and pointed out that
an agreement of this kind would, like the Antarctic and Outer Space treaties, "prevent an arms
race before it has a chance to start."
On March 18, 1969, the Soviet Union presented a draft Treaty that provided for the complete
demilitarization of the seabed beyond a 12-mile limit and making all seabed installations open to
Treaty parties on the basis of reciprocity. The U.S. draft Treaty, submitted on May 22, prohibited
the emplacement of nuclear weapons and other weapons of mass destruction on the seabed and
ocean floor beyond a three-mile band. This, the United States held, was the urgent problem, and
complete demilitarization would not be verifiable.
As can be seen, the two drafts differed importantly on what was to be prohibited. The Soviet
draft would have banned all military uses of the seabed. It would have precluded, for example,
submarine surveillance systems that were fixed to the ocean floor. The United States regarded
these as essential to its defense.
The two drafts also differed on the issue of verification. Using as a model the provisions for
verification in the Outer Space Treaty, the Soviets proposed that all installations and structures
be open to inspection, provided that reciprocal rights to inspect were granted. The United States
contended that on the Moon no claims of national jurisdiction existed and that provisions suitable
for the Moon would not be adequate for the seabed, where many claims of national jurisdiction
already existed and many kinds of activities were in progress or possible. Moreover, the United
States felt that to attempt to inspect for the emplacement of all kinds of weapons would make the
problems connected with verification virtually insuperable.
On the other hand, the United States stated the case that any structures capable of handling
nuclear devices would necessarily be large and elaborate; their installation would require
extensive activity, difficult to conceal; and there would probably be a number of devices
involved, as it would not be worth violating the Treaty simply to install one or two weapons.
Violations, therefore, would be readily observed and evoke the appropriate steps -- first an effort
to deal directly with the problem through consultations with the country violating the Treaty; if
that failed, recourse to cooperative action; and, as a last resort, appeal to the Security Council.
Comments on the two drafts in the ENDC, U.S. consultations with its NATO allies, and private
U.S.-Soviet talks at the ENDC eventually led to the framing of a joint draft by the United States
and the Soviet Union, submitted on October 7, 1969, to the CCD. This joint draft underwent
intensive discussion and was three times revised in response to suggestions made in the CCD and
at the United Nations.
Discussion centered on a few difficult issues. In international law there was much confusion
about how territorial waters were to be defined. Some countries claimed up to 200 miles, and
international conventions on the subject contained ambiguities. In its final form the Treaty
adopted a 12-mile limit to define the seabed area.
The verification provisions also were a subject of intensive discussion. Coastal states were
concerned about whether their rights would be protected. Smaller states had doubts as to their
ability to check on violations. Some felt that the United Nations should play a larger role. Some
wondered whether the verification procedures would really be effective. Reassurances were
given to the coastal states. Smaller states could apply for assistance to another state to help it in
case of a suspected violation.
The verification procedures are set forth in Article III. Parties may undertake verification using
their own means, with the assistance of other parties, or through appropriate international
procedures within the framework of the United Nations and in accordance with its Charter. These
provisions permit parties to assure themselves the Treaty obligations are being fulfilled without
interfering with legitimate seabed activities.
After more than two years of negotiation, the final draft was approved by the U.N. General
Assembly on December 7, 1970, by a vote of 104 to 2 (El Salvador, Peru), with two abstentions
(Ecuador and France).
Article I sets forth the principal obligation of the Treaty. It prohibits parties from emplacing
nuclear weapons or weapons of mass destruction on the seabed and the ocean floor beyond a
12-mile coastal zone. Article II provides that the "seabed zone" is to be measured in accordance
with the provisions of the 1958 Convention on the Territorial Sea and the Contiguous Zone. To
make clear that none of the Treatys provisions should be interpreted as supporting or prejudicing
the positions of any party regarding law-of-the-sea issues, a broad disclaimer provision to this
effect was included as Article IV.
In recognition of the feeling that efforts to achieve a more comprehensive agreement should
continue, Article V of the Treaty bound parties to work for further measures to prevent an arms
race on the seabed.
The Seabed Arms Control Treaty was opened for signature in Washington, London, and Moscow
on February 11, 1971. It entered into force May 18, 1972, when the United States, the United
Kingdom, the Soviet Union, and more than 22 nations had deposited instruments of ratification.
Article VII included a provision for a review conference to be held in five years. The Seabed
Arms Control Treaty Review Conference was held in Geneva June 20 - July 1, 1977. The
Conference concluded that the first five years in the life of the Treaty had demonstrated its
effectiveness. The Second Review Conference, held in Geneva in September 1983, concluded
that the Treaty continued to be an important and effective arms control measure. The Third
Review Conference was held in Geneva in September 1989 and confirmed results of previous
meetings. It was agreed that the next review conference would be convened in Geneva not earlier
1 As noted elsewhere, the Geneva-based ENDC (Eighteen-Nation Disarmament Committee)
became known as the CCD (Conference of the Committee on Disarmament) after its enlargement
TREATY ON THE PROHIBITION OF THE EMPLACEMENT OF NUCLEAR
WEAPONS AND OTHER WEAPONS OF MASS DESTRUCTION ON THE SEABED
AND THE OCEAN FLOOR AND IN THE SUBSOIL THEREOF
Signed at Washington, London, and Moscow February 11, 1971
Ratification advised by U.S. Senate February 15, 1972
Ratified by U.S. President April 26, 1972
U.S. ratification deposited at Washington, London, and Moscow May 18, 1972
Proclaimed by U.S. President May 18, 1972
Entered into force May 18, 1972
The States Parties to this Treaty,
Recognizing the common interest of mankind in the progress of the exploration and use of the
seabed and the ocean floor for peaceful purposes,
Considering that the prevention of a nuclear arms race on the seabed and the ocean floor serves
the interests of maintaining world peace, reduces international tensions and strengthens friendly
relations among States,
Convinced that this Treaty constitutes a step towards the exclusion of the seabed, the ocean floor
and the subsoil thereof from the arms race,
Convinced that this Treaty constitutes a step towards a Treaty on general and complete
disarmament under strict and effective international control, and determined to continue
negotiations to this end,
Convinced that this Treaty will further the purposes and principles of the Charter of the United
Nations, in a manner consistent with the principles of international law and without infringing
the freedoms of the high seas,
Have agreed as follows:
1. The States Parties to this Treaty undertake not to emplant or emplace on the seabed and the
ocean floor and in the subsoil thereof beyond the outer limit of a seabed zone, as defined in
article II, any nuclear weapons or any other types of weapons of mass destruction as well as
structures, launching installations or any other facilities specifically designed for storing, testing
or using such weapons.
2. The undertakings of paragraph 1 of this article shall also apply to the seabed zone referred to
in the same paragraph, except that within such seabed zone, they shall not apply either to the
coastal State or to the seabed beneath its territorial waters.
3. The States Parties to this Treaty undertake not to assist, encourage or induce any State to carry
out activities referred to in paragraph 1 of this article and not to participate in any other way in
For the purpose of this Treaty, the outer limit of the seabed zone referred to in article I shall be
coterminous with the twelve-mile outer limit of the zone referred to in part II of the Convention
on the Territorial Sea and the Contiguous Zone, signed at Geneva on April 29, 1958, and shall be
measured in accordance with the provisions of part I, section II, of that Convention and in
accordance with international law.
1. In order to promote the objectives of and insure compliance with the provisions of this Treaty,
each State Party to the Treaty shall have the right to verify through observations the activities of
other States Parties to the Treaty on the seabed and the ocean floor and in the subsoil thereof
beyond the zone referred to in article I, provided that observation does not interfere with such
2. If after such observation reasonable doubts remain concerning the fulfillment of the
obligations assumed under the Treaty, the State Party having such doubts and the State Party that
is responsible for the activities giving rise to the doubts shall consult with a view to removing the
doubts. If the doubts persist, the State Party having such doubts shall notify the other States
Parties, and the Parties concerned shall cooperate on such further procedures for verification as
may be agreed, including appropriate inspection of objects, structures, installations or other
facilities that reasonably may be expected to be of a kind described in article I. The Parties in the
region of the activities, including any coastal State, and any other Party so requesting, shall be
entitled to participate in such consultation and cooperation. After completion of the further
procedures for verification, an appropriate report shall be circulated to other Parties by the Party
that initiated such procedures.
3. If the State responsible for the activities giving rise to the reasonable doubts is not identifiable
by observation of the object, structure, installation or other facility, the State Party having such
doubts shall notify and make appropriate inquiries of States Parties in the region of the activities
and of any other State Party. If it is ascertained through these inquiries that a particular State
Party is responsible for the activities, that State Party shall consult and cooperate with other
Parties as provided in paragraph 2 of this article. If the identity of the State responsible for the
activities cannot be ascertained through these inquiries, then further verification procedures,
including inspection, may be undertaken by the inquiring State Party, which shall invite the
participation of the Parties in the region of the activities, including any coastal State, and of any
other Party desiring to cooperate.
4. If consultation and cooperation pursuant to paragraphs 2 and 3 of this article have not removed
the doubts concerning the activities and there remains a serious question concerning fulfillment
of the obligations assumed under this Treaty, a State Party may, in accordance with the
provisions of the Charter of the United Nations, refer the matter to the Security Council, which
may take action in accordance with the Charter.
5. Verification pursuant to this article may be undertaken by any State Party using its own
means, or with the full or partial assistance of any other State Party, or through appropriate
international procedures within the framework of the United Nations and in accordance with its
6. Verification activities pursuant to this Treaty shall not interfere with activities of other States
Parties and shall be conducted with due regard for rights recognized under international law,
including the freedoms of the high seas and the rights of coastal States with respect to the
exploration and exploitation of their continental shelves.
Nothing in this Treaty shall be interpreted as supporting or prejudicing the position of any State
Party with respect to existing international conventions, including the 1958 Convention on the
Territorial Sea and the Contiguous Zone, or with respect to rights or claims which such State
Party may assert, or with respect to recognition or non-recognition of rights or claims asserted by
any other State, related to waters off its coasts, including, inter alia, territorial seas and
contiguous zones, or to the seabed and the ocean floor, including continental shelves.
The Parties to this Treaty undertake to continue negotiations in good faith concerning further
measures in the field of disarmament for the prevention of an arms race on the seabed, the ocean
floor and the subsoil thereof.
Any State Party may propose amendments to this Treaty. Amendments shall enter into force for
each State Party accepting the amendments upon their acceptance by a majority of the States
Parties to the Treaty and, thereafter, for each remaining State Party on the date of acceptance by
Five years after the entry into force of this Treaty, a conference of Parties to the Treaty shall be
held at Geneva, Switzerland, in order to review the operation of this Treaty with a view to
assuring that the purposes of the preamble and the provisions of the Treaty are being realized.
Such review shall take into account any relevant technological developments. The review
conference shall determine, in accordance with the views of a majority of those Parties attending,
whether and when an additional review conference shall be convened.
Each State Party to this Treaty shall in exercising its national sovereignty have the right to
withdraw from this Treaty if it decides that extraordinary events related to the subject matter of
this Treaty have jeopardized the supreme interests of its country. It shall give notice of such
withdrawal to all other States Parties to the Treaty and to the United Nations Security Council
three months in advance. Such notice shall include a statement of the extraordinary events it
considers to have jeopardized its supreme interests.
The provisions of this Treaty shall in no way affect the obligations assumed by States Parties to
the Treaty under international instruments establishing zones free from nuclear weapons.
1. This Treaty shall be open for signature to all States. Any State which does not sign the Treaty
before its entry into force in accordance with paragraph 3 of this article may accede to it at any
2. This Treaty shall be subject to ratification by signatory States. Instruments of ratification and
of accession shall be deposited with the Governments of the United States of America, the
United Kingdom of Great Britain and Northern Ireland, and the Union of Soviet Socialist
Republics, which are hereby designated the Depositary Governments.
3. This Treaty shall enter into force after the deposit of instruments of ratification by twenty-two
Governments, including the Governments designated as Depositary Governments of this Treaty.
4. For states whose instruments of ratification or accession are deposited after the entry into force
of this Treaty, it shall enter into force on the date of the deposit of their instruments of
ratification or accession.
5. The Depositary Governments shall promptly inform the Governments of all signatory and
acceding States of the date of each signature, of the date of deposit of each instrument of
ratification or of accession, of the date of the entry into force of this Treaty, and of the receipt of
6. This Treaty shall be registered by the Depositary Governments pursuant to Article 102 of the
Charter of the United Nations.
This Treaty, the English, Russian, French, Spanish and Chinese texts of which are equally
authentic, shall be deposited in the archives of the Depositary Governments. Duly certified
copies of this Treaty shall be transmitted by the Depositary Governments to the Governments of
the States signatory and acceding thereto.
IN WITNESS WHEREOF the undersigned, being duly authorized thereto, have signed this
DONE in triplicate, at the cities of Washington, London and Moscow, this eleventh day of
February, one thousand nine hundred seventy-one.