A more remote fear of internal division is alluded to in the clause about states entering into alliances with each other. Those who drafted the Articles were well aware of the power of unity in opposing a governing force. They anticipated that states might become unhappy with the central government. In this light, the writers of the Articles attempted to eliminate the possibility that states could join in unity against the government. However, the wording is weak and emphasizes the inability of Congress to enforce its rulings. This clause implies that as long as states inform congress of their alliance, the alliance is okay. Even if Congress prohibited the alliance, how could it force the alliance to end?
The trade meeting between Maryland and Virginia that took place at Mount Vernon in 1786 is a perfect example of what was disallowed by the Articles of Confederation. Congress did nothing at all to stop this meeting or alliance, and when an additional meeting was scheduled at Annapolis, inviting all of the states into a commercial alliance, Congress still did nothing. Congress had good reason to perceive this alliance as a threat, since it served to undermine its authority by re-making the Articles of Confederation. However, in its powerless position, Congress did nothing.
Article 6 is also significant in the way in which it expresses the relationship between Congress and the states with regard to commerce. States are not allowed to partake in any sort of foreign diplomacy or treaty making—that power is reserved for Congress. However, Congress is not granted the power to make imposts on foreign trade. Therefore, each state is allowed to determine its own imposts, as long as it doesn't interfere with the terms of foreign treaties made by Congress.
The phrasing of the clause on imposts leaves a huge flexibility of interpretation, allowing states to determine their imposts. The allowance of such flexibility demonstrates the powerlessness of Congress when it came to taxes of any kind. All of the other clauses in this Article assert that a state may not do something (such as make war), without the approval of Congress. In the impost clause the necessary approval of Congress is noticeably missing because Congress does not possess any authority over imposts. Therefore, the judgment is left to the states, not to Congress, about the permissibility of each impost.
Article 6, in attempting to define the limitations of state powers, actually does more to indicate the threats facing the young nation and the powerless nature of Congress. Even the powers given exclusively to Congress, such as making war and peace, are transferable to a state when Congress approves. A weak Congress lacking the power of enforcement could have been powerless to stop a state that usurped the congressional power of making war. Fortunately, the only usurpation of power that it was unable to stop, the Mount Vernon Conference, ultimately resulted in a strengthening of national power.