The topic of discussion for this Constitution Monday comes from Article I, Section 10, Clause 1: "No State shall enter into any Treaty,
, or Confederation…." Section 8 of the U.S. Constitution specifically granted to Congress the power and authority to make treaties, alliances, and/or confederations; therefore, this provision merely reminds the States that the federal government has the right and the responsibility to handle these specific duties. Alliance
"All of the powers denied to the states in this section are those which are specifically granted to the national government in section 8. The states had exercised these powers under the Articles of Confederation and had nearly wrecked the government. That is why the Founders took this extra precaution to spell out these powers as belonging to the national government after the adoption of the federal charter" (W. Cleon Skousen, The Making of America - The Substance and Meaning of the Constitution, p. 492).
The Articles of Confederation (Article VI) allowed the states to make treaties with foreign governments as long as Congress approved. "In addition to granting the government powers to regulate trade and raise revenue that it either lacked or could not enforce under the Articles of Confederation, the Framers intended the Constitution to centralize much, if not all, power over foreign affairs. Many of the federal government's enumerated powers relate to foreign affairs and have corresponding restrictions on states in Article I, Section 10….
"Treaties, as well as alliances and confederations, are formal, binding agreements between nations that are the subjects of international law…." (Brannon P. Denning, The Heritage Guide to the Constitution, pp. 167-168).
The Founders wrote the Constitution in such a way as to allow for a strong, central government to handle national affairs while at the same time allowing States to handle local affairs. They obviously could see that big problems could come from having both States and the central government entering into treaties, etc. with foreign governments.