[Senate Executive Report 106-19]
[From the U.S. Government Publishing Office]

106th Congress                                              Exec. Rept.
 2d Session                                                      106-19




               September 29, 2000.--Ordered to be printed


          Mr. Helms, from the Committee on Foreign Relations,
                        submitted the following

                              R E P O R T

                   [To accompany Treaty Doc. 106-39]

    The Committee on Foreign Relations, to which was referred 
the Treaty Between the Government of the United States of 
America and the Government of the United Mexican States on the 
Delimitation of the Continental Shelf in the Western Gulf of 
Mexico Beyond 200 Nautical Miles, signed at Washington on June 
9, 2000 (Treaty Doc. 106-39) having considered the same, 
reports favorably thereon with the declaration and proviso 
indicated in Section VII, and recommends that the Senate give 
its advice and consent to the ratification thereof as set forth 
in this report and the accompanying resolution of ratification.



  I. Purpose..........................................................1
 II. Background.......................................................1
III. Summary..........................................................3
 IV. Entry Into Force and Denunciation................................3
  V. Committee Action.................................................4
 VI. Committee Recommendation and Comments............................4
VII. Text of Resolution of Ratification...............................4

                               I. Purpose

    The treaty addresses the delineation of the Continental 
Shelf boundary in the Gulf of Mexico between the United States 
and Mexico.

                             II. Background

    The proposed treaty was preceded by two related agreements. 
Under the Treaty to Resolve Pending Boundary Differences and to 
Maintain the Rio Grande and Colorado River as the International 
Boundary (23 UST 371; TIAS 7313 (1972)), a maritime boundary 
was established, inter alia, in the western Gulf of Mexico 
extending approximately 12 nautical miles into the Gulf from 
the land boundary separating Mexico and Texas (the mouth of the 
Rio Grande River). That treaty entered into force in 1972.
    Mexico then claimed an exclusive economic zone, and the 
United States a fisheries management zone, extending 200 
nautical miles from their shores. These zones overlapped in 
parts of the Gulf. Consequently, the U.S. and Mexico negotiated 
provisional boundaries in 1976 and, finding them to be 
satisfactory, incorporated them into a 1978 ``Treaty on 
Maritime Boundaries between the United States of America and 
the United Mexican States'' (``1978 Treaty'').
    The 1978 treaty established a further delineation of the 
maritime boundaries between Mexico and the United States 
extending from the end of the previous boundary line to 200 
miles into the western part of the Gulf of Mexico. The treaty 
also established a boundary line in the eastern part of the 
Gulf of Mexico where the zones overlapped, by virtue of each 
country's claim measured from Louisiana for the United States, 
and from several Mexican islands off the coast of Yucatan for 
    Although the 1978 Treaty was favorably reported by the 
Senate Committee on Foreign Relations in 1980 (S. Exec. Rept. 
No. 96-49, 96th Cong., 2d Sess. (August 5, 1980)), its approval 
by the full Senate was delayed by differences over the oil and 
gas potential of the area ceded to Mexico. The 1978 Treaty was 
eventually ratified, however, in 1997.
    Between the western and eastern boundaries established by 
the 1978 Treaty there remained a substantial deep sea area of 
the Gulf (about 135 miles long and comprising approximately 
6600 square miles) that lay beyond either of the claimed 
zones--the so-called ``Western Gap.''
    The Clinton Administration expressed its intent to enter 
into negotiations with Mexico to delimit the continental shelf 
in the Western Gap once the 1978 Treaty was ratified. The 1997 
report of the Committee on Foreign Relations on the 1978 Treaty 
supported commencement of negotiations, stating:

          Delimitation of the western gap has become 
        increasingly important to U.S. interests as petroleum 
        exploration has moved into deeper waters. The 
        Department of Interior is now receiving bids for 
        exploration in this area. Several new drilling vessels 
        capable of operating in water depths of up to 10,000 
        feet are under construction * * *. The Committee urges 
        the Executive Branch to commence negotiations on the 
        western gap without delay, once this treaty enters into 
        force (S. Exec. Rept. 105-4, 105th Cong., 1st Sess., at 
        5-6 (Oct. 22, 1997)).

    The proposed treaty discussed in this report is the product 
of those negotiations.

                              III. Summary

                               A. GENERAL

    The proposed treaty would establish a boundary between the 
two countries on the continental shelf of the Western Gap. 
Treaty Doc. 106-39 sets forth an illustrative diagram of the 
affected area and coordinates. The waters above this area are, 
and will remain, international waters.
    The treaty is intended to clarify each country's right to 
exploit the resources of the seabed and subsoil in the affected 
region, particularly the oil and gas resources that may be 
there. The treaty would also provide a means for resolving 
conflicting claims to oil and gas deposits that may extend 
across the boundary (``transboundary reservoirs''). The 
division allocates approximately 4100 square miles (62%) of the 
Western Gap to Mexico and 2536 square miles (38%) to the United 

                           B. KEY PROVISIONS

    Articles I and II of the proposed treaty define the 
boundary line by means of geodetic lines between specified 
    Article III bars the United States from exercising any 
sovereign rights or jurisdiction over the seabed and subsoil 
south of that line, and Mexico from doing so north of that 
    Article IV defines an area extending 1.4 nautical miles on 
either side of the boundary line (``the Area''), and prohibits 
drilling or other exploitation in the Area for a period of ten 
years (or such other period as the Parties agree to). It also 
mandates cooperation between the two countries in determining 
the existence and location of transboundary reservoirs in the 
    Article V requires the Parties, during the period of the 
moratorium on exploitation in the Area, to ``seek to reach 
agreement for the efficient and equitable exploitation of such 
transboundary reservoirs.''
    Article V further requires each Party, after the expiration 
of the moratorium, to inform the other of decisions to 
authorize exploration, development, and production in the Area.
    Article VI requires each Party to honor requests from the 
other for consultations on the interpretation and 
implementation of the treaty.
    Article VII contains standard language to the effect that 
the boundary established by this treaty does not prejudice or 
affect either Party's claims regarding its internal waters, the 
territorial sea, the high seas, or for any other purpose.
    Article VIII mandates that disputes over the treaty be 
resolved by negotiation or other peaceful means.

                 IV. Entry into Force and Denunciation

                          A. ENTRY INTO FORCE

    Pursuant to Article IX, the proposed treaty will enter into 
force on the date of the exchange of instruments of 

                             B. TERMINATION

    The proposed treaty contains no termination provision.

                          V. Committee Action

    The Committee on Foreign Relations held a public hearing on 
the proposed treaty on September 13, 2000, (a transcript of the 
hearing and questions for the record can be found in Senate 
hearing 106-660 entitled ``Consideration of Pending 
Treaties''). The Committee considered the proposed treaty on 
September 27, 2000, and ordered it favorably reported by voice 
vote, with the recommendation that the Senate give its advice 
and consent to the ratification of the proposed treaty subject 
to the declaration and proviso noted below.

               VI. Committee Recommendation and Comments

    The Committee on Foreign Relations recommends favorably the 
proposed treaty. On balance, the Committee believes that the 
proposed treaty is in the interest of the United States and 
urges the Senate to act promptly to give its advice and consent 
to ratification.

              VII. Text of the Resolution of Ratification

      Resolved, (two thirds of the Senators present concurring 
therein), That the Senate advise and consent to the 
ratification of the Treaty between the Government of the United 
States of America and the Government of the United Mexican 
States on the Delimitation of the Continental Shelf in the 
Western Gulf of Mexico beyond 200 Nautical Miles, signed at 
Washington on June 9, 2000 (Treaty Doc. 106-39), subject to the 
declaration of subsection (a) and the proviso of subsection 
      (a) Declaration.--The Senate's advice and consent is 
subject to the following declaration, which shall be binding 
upon the President:
            Treaty Interpretation.--The Senate affirms the 
        applicability to all treaties of the constitutionally 
        based principles of treaty interpretation set forth in 
        Condition (1) of the resolution of ratification of the 
        INF Treaty, approved by the Senate on May 27, 1988, and 
        Condition (8) of the resolution of ratification of the 
        Document Agreed Among the States Parties to the Treaty 
        on Conventional Armed Forces in Europe, approved by the 
        Senate on May 14, 1997.
      (b) Proviso.--The resolution of ratification is subject 
to the following proviso, which shall not be included in the 
instrument of ratification:
            Supremacy of the Constitution.--Nothing in this 
        Treaty requires or authorizes legislation or other 
        action by the United States of America that is 
        prohibited by the Constitution of the United States as 
        interpreted by the United States.