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Chapter 1: Treaties
Chapter 2: Precedents, Negotiators, Bipartisanship
Chapter 3: Senate Options
Chapter 4: Executive Agreements, Treaty Termination, Status as Law
Chapter 5: Rejected Treaties


The Constitution gives the Senate the power to approve, by a two-thirds vote, treaties made by the executive branch.

The Senate has rejected relatively few of the hundreds of treaties it has considered in its history. Many others, however, have died in committee or been withdrawn by the president rather than face defeat.

Some presidents have found it helpful to include senators in negotiating treaties in order to help pave the way for later Senate approval.

The requirement for a two-thirds vote ensures that a treaty will need bipartisan support to be approved.

The Senate may also amend a treaty or adopt various changes, which may lead the other nation, or nations, to further negotiate the treaty.

The president may also enter into executive agreements with foreign nations that are not subject to Senate approval.

Constitutional Provisions

Article II, section 2, of the Constitution states that the president "shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two-thirds of the Senators present concur." These few words are the cornerstone to a major part of our system of divided powers, checks and balances.

According to one scholar of the early Senate, "the Senate power which aroused the gravest and most widespread apprehension was that associated with the making of treaties." The Constitution's framers gave the Senate a share of the treaty power in order to check presidential power, to give the president the benefit of the Senate's advice and counsel, and to safeguard the sovereignty of the states by giving each state an equal vote in the treatymaking process.

On August 22, 1789, President George Washington and Secretary of War Henry Knox presented the Senate with a series of questions relating to treaties with various Indian tribes. The Senate voted to refer these to a committee rather than debate the issue in the presence of the august president, who seemed to overawe many of the senators. Washington decided that, in the future, he would send to the Senate communications regarding treaties only in writing, setting the precedent that all of his successors have followed.

Jay's Treaty

The most important treaty that the Senate considered during the Washington administration, and one that established important precedents, was negotiated by Chief Justice John Jay to settle disputes with Great Britain. Washington sent Jay to London at the urging of five Federalist party senators but failed to consult the full Senate in 1795 before requesting their advice and consent to the completed treaty. Although the treaty's opponents supported New York Senator Aaron Burr's motion to reopen the negotiations, pursuant to a set of specific proposals, the Federalists defeated that plan and its notion that "the Senate would . . . expect to participate in framing the conditions" of future treaties.

Approval of the unpopular Jay Treaty on June 24, 1795, brought the Senate under considerable public attack. The House of Representatives used this fervor in an attempt to expand its own role in foreign affairs. While Federalist supporters of the Jay Treaty held the majority in the Senate, the House was controlled by Jeffersonian Republicans, who opposed the treaty and threatened to withhold the funding necessary to effect some of its provisions. The appropriation ultimately passed the House on April 30, 1796 by a narrow margin, a critical victory for the Senate's unique and vital role in the making of treaties.

The Jay Treaty set another significant precedent - its injunction of secrecy. Throughout the nineteenth and early twentieth centuries, the Senate attempted to deliberate on treaties in secret session. With regular efficiency, the newspapers managed to breach that secrecy and publish astonishingly complete accounts of the secret discussions, sometimes printing the text of a treaty before the senators got their official copies. The Senate investigated, fretted, and howled but proved powerless to stop the leaks, which came from the members themselves. Not until 1929 were executive sessions routinely opened to the press and the public. Today the Senate holds closed sessions only under the rarest of circumstances.

Precedents, Negotiators, Bipartisanship


As the new government evolved, new precedents shaped the treatymaking process. In 1794, the Senate "suspended" one article of the Jay Treaty as a means of preventing rejection of the whole. In 1803, the Senate added an amendment, which Great Britain refused to accept, to the King-Hawksbury Convention. The power to amend treaties after they had been signed rapidly replaced Washington's earlier expectation of Senate advice during the negotiations. This power to amend became so significant that, in 1868, the Senate changed its rules to permit amendments to treaties by a simple majority vote. This change gave senators greater leeway in changing the content of treaties, but also permitted opponents to add amendments which would cause senators who had initially supported the treaty to reject the final text. The ability to amend by a simple majority vote can also, however, be the means of putting together the necessary two-thirds vote for final approval, as in the case of the Panama Canal treaties in 1978.

In rejecting a treaty with the Wabash and Illinois Indians, the Senate in 1794, for the first time, exercised its right to refuse its consent to a treaty negotiated by the executive branch. In 1825, the Senate first rejected an international treaty, turning down, by a vote of 0 to 40, a convention with Colombia for the suppression of the slave trade. The Senate has rejected relatively few of the hundreds of treaties it has considered in its more than two-hundred-year history. Many others, however, have died in committee or been withdrawn by the president rather than face defeat.

One of the thorny issues that surfaced early in the Senate's history was whether the "advice and consent" of the Senate was required prior to the negotiations leading to the making of treaties. Presidents Washington, Polk, Lincoln, Grant, and several others on occasion sought the advice of the Senate before entering into conventions and treaties. In the controversy surrounding the Jay Treaty, Attorney General Edmund Randolph maintained that to proceed otherwise would abridge the rights of the Senate.

Senators as Negotiators

Another vexing issue that has surfaced many times is whether senators should be involved in the actual negotiation of treaties. During the War of 1812, Delaware Senator James Bayard was a member of the delegation to negotiate the Treaty of Ghent. His presence raised the question of whether having senators on the negotiating team would make the Senate more favorably inclined to approve the treaty, or whether it would violate the separation of powers. That debate has gone on for many generations without being resolved.

Noting the frequency with which the Senate had rejected treaties during the last quarter of the nineteenth century, President William McKinley shrewdly named three U.S. senators to negotiate the treaty of peace with Spain in 1898. Senators from both parties roundly criticized his action, but the Senate ultimately approved the resulting treaty. A generation later, President Woodrow Wilson was criticized for not including senators in the delegation that negotiated the Treaty of Versailles, ending World War I and establishing the League of Nations. While this omission contributed to the defeat of that treaty, which was twice rejected by the Senate, the president's party had lost control of the Senate in 1918, and the new chairman of the Foreign Relations Committee was his bitter political opponent, Henry Cabot Lodge, Sr. Had Wilson taken any senators to Europe, he could not have avoided taking Lodge, who was also the Senate's Republican leader.

With the Treaty of Versailles in mind, Wilson's successor, Warren G. Harding--who had served as a senator during the fight for the treaty's ratification--in 1921 appointed Senator Lodge and Senate Democratic Leader Oscar Underwood as delegates to the Washington Arms Limitation Conference. For very much the same reason, Presidents Franklin Roosevelt and Harry Truman involved the chairman and the ranking Republican of the Senate Foreign Relations Committee in the creation of the United Nations. This action spared the U.N. the fate of the League of Nations; there were only two Senate votes against its charter.

One solution to the problem of senators as negotiators has been for presidents to invite whole senatorial delegations to visit ongoing negotiations. On February 28, 1985, the Senate adopted a resolution creating a bipartisan Senate Observer Group to act as official observers at the Arms Reduction and Control Negotiations in Geneva between the United States and the Soviet Union. On January 6, 1987, the Senate adopted a resolution reauthorizing and redesignating the Senate Arms Control Observer Group. The negotiations resulted in the signing of the Intermediate-Range Nuclear Forces (INF) treaty in Washington on December 8, 1987. The senators in the observer group did not participate in the actual negotiations, but provided a continuing important link between the Senate and the Ronald Reagan administration's negotiators, keeping the Senate informed regarding developments and progress in the negotiations, and periodically advising and consulting with the U.S. negotiators.


The Constitution specifies that Senate consent to ratification of treaties requires a two-thirds vote. The effect of this requirement is that successful treatymaking can never be a partisan affair, since only under the rarest circumstances has a party ever enjoyed a two-thirds majority in the Senate. Treaties must reflect a broad national consensus. The two-thirds requirement adds to the burdens of the Senate leadership, and may also encourage opponents of a treaty to engage in a variety of dilatory tactics in hopes of obtaining sufficient votes to insure its defeat. Several of the treaties rejected by the Senate received more "ayes" than "noes" but failed to receive the necessary two-thirds.

Senate Options

The Senate, itself, does not ratify treaties--actual ratification only takes place when the instruments of ratification are formally exchanged between the parties. When a treaty is submitted to the Senate for approval, it has several options for action. Depending on whether or not a two-thirds majority votes in favor, the Senate may approve or reject the treaty as it has been submitted. It may make its approval conditional by including in the resolution amendments to the text of the treaty, reservations, understandings, interpretations, declarations, or other statements. The president and the other countries involved must then decide whether to accept the conditions and changes in the legislation, renegotiate the provisions, or abandon the treaty. Finally, the Senate may choose to take no definitive action, leaving the treaty pending in the Senate until withdrawn at the request of the president or, occasionally, at the initiative of the Senate.

Most treaties submitted to the Senate have received its advice and consent to ratification, and the ratification has subsequently been signed and deposited in the National Archives by the president. During its first two hundred years, the Senate approved more than 1,500 treaties, approximately 90 percent of those submitted to it. To date, only 21 treaties have been rejected by a Senate vote because they failed to receive the required two-thirds majority, the most recent being the October 13, 1999 vote to reject the Comprehensive Nuclear Test Ban Treaty. A number of these, including the Treaty of Versailles, were rejected twice. Most often, the Senate has simply not voted on treaties that its leadership deemed not to have sufficient support within the Senate for approval, and in general these treaties have eventually been withdrawn.

On a number of occasions, the Senate has exercised its role in the treatymaking process in such a way that treaties never entered into force. Of the many treaties approved by the Senate with amendments, reservations, understandings, or interpretations, forty-three never entered into force because the reservations or amendments were not acceptable either to the president or to the other country or countries party to the treaty.

An amendment makes an actual change in the language of the treaty. Also available to the Senate are other options, short of outright rejection of a treaty. The terminology of these limiting actions varies. Although the labeling of the Senate's expression may be relatively unimportant in determining its legal effect, the most significant actions, in order of their impact, are: amendments; reservations; understandings; interpretations; declarations; and statements, or similar wording such as clarification, recommendation, explanation, or sense of the Senate.

Regardless of what an action is called, the substance determines the legal effect. For example, language would constitute a reservation (or an amendment) when it would exclude or vary the legal effect of one or more of the provisions of the treaty. On the other hand, language which merely explains or clarifies the meaning of treaty provisions but does not exclude or vary the legal effect of such provisions would properly constitute an understanding or interpretation. Often, there can be confusion in the use of a particular label or descriptive term for what is being done, but the substance is what counts, and there can, in fact, be little difference in effect between a reservation and an amendment depending on its content. A reservation that limits the U.S. obligation may have the same effect as an amendment to the actual text of the treaty itself. Conversely, an understanding or declaration may often simply deal with some matter incidental to the operation of the treaty in a manner other than as a substantive reservation. Even though such language may have no effect in the international obligations of the treaty, however, the executive would communicate such interpretations or understandings to the other parties. If, regardless of its label, the U.S. government believes that the verbiage has the actual character of an amendment, condition, or reservation, it would be so treated and transmitted to the other signatory state or states, and it could be subject to further negotiations if not rejected outright by the other state.

At least eighty-five treaties were eventually withdrawn because the Senate never took final action on them. Treaties may also remain in the Senate Foreign Relations Committee for extended periods since treaties are not required to be resubmitted at the beginning of each new Congress. There have been instances in which treaties have lain dormant within the committee for years, even decades, without action being taken.

Senate action is not the only reason that various treaties signed by the United States have remained "unperfected treaties" and never entered into force. In some cases, the president has simply not submitted treaties to the Senate although they have been signed. In others, the ratification process has not been completed by the president even though the Senate has given its approval. In still other cases, treaties have not taken effect because of actions of other nations.

Executive Agreements, Treaty Termination, Status as Law

Executive Agreements

In addition to treaties, which may not enter into force and become binding on the United States without the advice and consent of the Senate, there are other types of international agreements concluded by the executive branch and not submitted to the Senate. These are classified in the United States as executive agreements, not as treaties, a distinction that has only domestic significance. International law regards each mode of international agreement as binding, whatever its designation under domestic law.

The difficulty in obtaining a two-thirds vote was one of the motivating forces behind the vast increase in executive agreements after World War II. In 1952, for instance, the United States signed 14 treaties and 291 executive agreements. This was a larger number of executive agreements than had been reached during the entire century of 1789 to 1889. Executive agreements continue to grow at a rapid rate. The United States is currently a party to nearly nine hundred treaties and more than five thousand executive agreements.

The growth in executive agreements is also attributable to the sheer volume of business and contacts between the United States and other countries, coupled with the already heavy workload of the Senate. Many international agreements are of relatively minor importance and would needlessly overburden the Senate if they were submitted to it as treaties for advice and consent. Another factor has been the passage of legislation authorizing the executive branch to conclude international agreements in certain fields, such as foreign aid, agriculture, and trade. Treaties have also been approved implicitly authorizing further agreements between the parties. According to a 1984 study by the Senate Committee on Foreign Relations, "88.3 percent of international agreements reached between 1946 and 1972 were based at least partly on statutory authority; 6.2 percent were treaties, and 5.5 percent were based solely on executive authority."

Treaty Termination

The Constitution is silent about how treaties might be terminated. The breaking off of two treaties during the Jimmy Carter administration stirred controversy. In 1978, the president terminated the U.S. defense treaty with Taiwan, in order to facilitate the establishment of diplomatic relations with the People's Republic of China. Also in 1978, the new Panama Canal treaties replaced three previous treaties with Panama. In one case, the president acted unilaterally; in the second, he terminated treaties in accordance with actions taken by Congress. But clearly it seems that the right to terminate belongs to the executive, the sole branch of government that communicates with foreign governments. Only once has Congress terminated a treaty by a joint resolution; that was a mutual defense treaty with France, from which, in 1798, Congress declared the United States "freed and exonerated." In that case, breaking the treaty almost amounted to an act of war; indeed, two days later Congress authorized hostilities against France, which were only narrowly averted.

Status as Law

By virtue of the Constitution's supremacy clause (Article VI, clause 2) a treaty that is concluded compatibly with applicable constitutional requirements may have status as the "supreme law of the land," along with federal statutes and the Constitution itself. A treaty does not become effective as U.S. domestic law automatically, however, upon its entry into force on the international level. Instead, this occurs only where the instrument is "self-executing" and operates without any necessity for implementing legislation.

When the Constitution created an executive branch and a president of the United States, it gave him no unchecked or unconditional powers. The Constitution made treatymaking a concurrent power. The United States Senate has carefully guarded its share of this power for two hundred years.

The vast majority of treaties have been ratified by the Senate. Since 1789, only twenty-one treaties have been rejected by the full Senate.

Rejected Treaties

Date: March 9, 1825

Treatymaking Country: Colombia

Subject of Treaty: Suppression of African Slave Trade

Vote: Yeas=0; Nays=40


Date: June 11, 1836

Treatymaking Country: Switzerland

Subject of Treaty: Personal and property rights

Vote: Yeas=14; Nays=23


Date: June 8, 1844

Treatymaking Country: Texas

Subject of Treaty: Annexation

Vote: Yeas=16; Nays=35


Date: June 15, 1844

Treatymaking Country: German Zollverein

Subject of Treaty: Reciprocity

Vote: Yeas=26; Nays=18


Date: May 31, 1860

Treatymaking Country: Mexico

Subject of Treaty: Transit and commercial rights

Vote: Yeas=18; Nays=27


Date: June 27, 1860

Treatymaking Country: Spain

Subject of Treaty: Cuban Claims Commission

Vote: First vote, Yeas=25; Nays=17

Second vote, Yeas=24, Nays=18


Date: April 13, 1869

Treatymaking Country: Great Britain

Subject of Treaty: Arbitration of claims

Vote: Yeas=1; Nays=54


Date: June 1, 1870

Treatymaking Country: Hawaii

Subject of Treaty: Reciprocity

Vote: Yeas=20; Nays=19


Date: June 30, 1870

Treatymaking Country: Dominican Republic

Subject of Treaty: Annexation

Vote: Yeas=28; Nays=28


Date: January 15, 1883; April 20, 1886

Treatymaking Country: Mexico

Subject of Treaty: Mining claims

Vote: January 15, 1883, Yeas=33; Nays=20

April 20, 1886, Yeas=32; Nays=26


Date: January 29, 1885

Treatymaking Country: Nicaragua

Subject of Treaty: Interoceanic canal

Vote: Yeas=32; Nays=23


Date: August 21, 1888

Treatymaking Country: Great Britain

Subject of Treaty: Fishing rights

Vote: Yeas=27; Nays=30


Date: February 1, 1889

Treatymaking Country: Great Britain

Subject of Treaty: Extradition

Vote: Yeas=15; Nays=38


Date: May 5, 1897

Treatymaking Country: Great Britain

Subject of Treaty: Arbitration

Vote: Yeas=43; Nays=26


Date: November 19, 1919; March 19, 1920

Treatymaking Country: Multilateral

Subject of Treaty: Treaty of Versailles

Vote: November 19, 1919: Yeas=38; Nays=53

March 19, 1920: Yeas=49; Nays=35


Date: January 18, 1927

Treatymaking Country: Turkey

Subject of Treaty: Commercial rights

Vote: Yeas=50; Nays=34


Date: March 14, 1934

Treatymaking Country: Canada

Subject of Treaty: St. Lawrence Seaway

Vote: Yeas=46; Nays=42


Date: January 29, 1935

Treatymaking Country: Multilateral

Subject of Treaty: World Court

Vote: Yeas=52; Nays=36


Date: May 26, 1960

Treatymaking Country: Multilateral

Subject of Treaty: Law of the Sea Convention

Vote: Yeas=49; Nays=30

Note: This treaty remained on the calendar of the Senate Foreign Relations Committee until the 106th Congress, when it was returned to the President via S. Res. 267.


Date: March 8, 1983

Treatymaking Country: Multilateral

Subject of Treaty: Montreal Aviation Protocols

Vote: Yeas=50; Nays=42

Note: This treaty remained on the calendar of the Senate Foreign Relations Committee until the 105th Congress, when it was returned to the President as part of the resolution of ratification for Montreal Protocol No. 4 in 1998.


Date: October 13, 1999

Treatymaking Country: Multilateral

Subject of Treaty: Comprehensive Nuclear Test Ban Treaty

Vote: Yeas=48; Nays=51


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