Annex 1 to the Treaty assigns each state to one of six geographical regions for the purpose of determining Executive Council composition, in accordance with paragraph 28 of Article II. That paragraph assigns a specific number of seats to each of the six geographical regions, and paragraph 29 of Article II sets forth the procedures whereby each regional group must designate States Parties within that regional group for election to the Executive Council.

The listing of states in Annex 1 is designed to be comprehensive and includes not only those States that participated in the negotiations, but also all other states that are generally recognized as "states" under international law. Nevertheless, in the event that it becomes necessary, Paragraph 23 of Article II authorizes the Conference to add a state to Annex 1 by following the procedures set forth in paragraph 22 of Article II for decisions on matters of substance, i.e., consensus, or if consensus is not possible, decision by two-thirds majority of the members present and voting. Pursuant to paragraph 23 of Article II, any other changes to Annex 1, e.g., moving a state from one geographic region to another, requires a consensus decision of the Conference.

The division of states into six geographic regions constitutes a departure from the more common division into five regions that is employed by the UNGA, and that will be employed in the Organization for the Prohibition of Chemical Weapons. CTBT negotiators chose to divide states into six geographic regions primarily because such a structure would parallel the structure of the IAEA.

The first paragraph of Annex 2 to the Treaty sets forth a formula that determines the specific group of states that must have deposited their instruments of ratification in order for the Treaty to enter into force, pursuant to paragraph 1 of Article XIV. The formula is designed to satisfy two principal concerns that were raised during the negotiations. First, a number of states, including several nuclear weapon states, insisted upon a requirement that all nuclear weapon states and the three so-called "threshold states" sign the Treaty and deposit their instruments of ratification as a precondition for entry into force of the Treaty. Second, some negotiating states were unwilling to adopt a list of states that appeared arbitrary or that was limited to the nuclear weapon states and the threshold states. In addition, the negotiating states recognized that ratification by a certain minimum number of states would be needed to ensure the effective implementation of the Treaty. The formula addresses the two principal concerns by establishing two criteria for inclusion on the list of states required for entry into force of the Treaty.

The first criterion is that the state must have been a member of the Conference on Disarmament ("CD") on June 18, 1996. This date is significant because on June 17, 1996 the CD decided to expand its membership by adding a number of additional states, including Israel, one of the "threshold states." By using the expanded membership of the CD as an initial criterion, all of the nuclear weapon states and all of the "threshold states" are captured.

The second criterion is that the state must be included in either the IAEA list of states that have nuclear power reactors (Table 1 of the April 1996 edition of the IAEA's publication "Nuclear Power Reactors in the World,") or the IAEA list of states that have nuclear research reactors (Table I of the December 1995 edition of the IAEA's publication "Nuclear Research Reactors in the World.") Using the IAEA lists of states with nuclear reactors as a second criterion creates a reasonable, albeit indirect, linkage between those states required for entry into force of the Treaty and the subject matter of the Treaty.

In addition to the two above-mentioned criterion, a third criterion was added to address the unique status of the former Yugoslavia (the Socialist Federal Republic of Yugoslavia). Although Yugoslavia is a member of the CD, a number of CD members do not recognize the Federal Republic of Yugoslavia ("FRY") as the "continuation" of, or sole successor to, the former Yugoslavia. A compromise solution to this problem was worked out in the CD, whereby the CD retains a seat for the former Yugoslavia, but neither the FRY, nor any other of the former Yugoslavian entities is permitted to participate on its behalf.

Because inclusion of Yugoslavia in the list of states required for entry into force of the CTBT might be deemed formal recognition of the FRY by states that sign the Treaty, many states considered it necessary to adopt a formula that excluded Yugoslavia from the list of required states. Accordingly, a final criterion was added that requires the state to have formally participated in the work of the 1996 session of the CD. This effectively excludes the former Yugoslavia from the list.

The second paragraph of Annex 2 lists the forty-four states that meet all three of the criteria set forth in the first paragraph of the Annex. Those states are as follow: Algeria, Argentina, Australia, Austria, Bangladesh, Belgium, Brazil, Bulgaria, Canada, Chile, China, Colombia, Democratic People's Republic of Korea, Egypt, Finland, France, Germany, Hungary, India, Indonesia, Iran (Islamic Republic of), Israel, Italy, Japan, Mexico, Netherlands, Norway, Pakistan, Peru, Poland, Romania, Republic of Korea, Russian Federation, Slovakia, South Africa, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom of Great Britain and Northern Ireland, United States of America, Viet Nam, and Zaire. Pursuant to paragraph 1 of Article XIV, each of these states must sign the Treaty and deposit its instrument of ratification before the Treaty can enter into force.