The capacity of the United States to enter into agreements with other nations is not exhausted in the treaty-making power. The Constitution recognizes a distinction between
compacts but does not indicate what the difference is.1 The differences, which once may have been clearer, have been seriously blurred in practice within recent decades. Once a stepchild in the family in which treaties were the preferred offspring, the executive agreement has surpassed in number and perhaps in international influence the treaty formally signed, submitted for ratification to the Senate, and proclaimed upon ratification.
During the first half-century of its independence, the United States was party to sixty treaties but to only twenty-seven published executive agreements. By the beginning of World War II, there had been concluded approximately 800 treaties and 1,200 executive agreements. In the period 1940-1989, the Nation entered into 759 treaties and into 13,016 published executive agreements. Cumulatively, in 1989, the United States was a party to 890 treaties and 5,117 executive agreements. To phrase it comparatively, in the first 50 years of its history, the United States concluded twice as many treaties as executive agreements. In the 50-year period from 1839 to 1889, a few more executive agreements than treaties were entered into. From 1889 to 1939, almost twice as many executive agreements as treaties were concluded. Between 1939 and 1993, executive agreements comprised more than 90% of the international agreements concluded.2
One must, of course, interpret the raw figures carefully. Only a very small minority of all the executive agreements entered into were based solely on the powers of the President as Commander in Chief and organ of foreign relations; the remainder were authorized in advance by Congress by statute or by treaty provisions ratified by the Senate.3 Thus, consideration of the constitutional significance of executive agreements must begin with a differentiation among the kinds of agreements which are classed under this single heading.4