Each state must accept and agree to follow the decisions of the United States in Congress assembled. The states must follow all of the rules as stated in the Articles of Confederation. The union of states is meant to last forever. No alterations can be made to the Articles without the agreement of Congress and the confirmation by each of the state legislatures.
Each of the delegates that sign this document has the power to commit the state that they represent to all of the Articles and their specific contents. The people of each state will agree to follow the rulings of Congress on all matters they discuss, and each of the states agrees to never violate the union. We have signed this as members of Congress, meeting in Philadelphia, Pennsylvania on July 9, 1778, the third year of American Independence.
Article 13 and the conclusion provide the means by which the Articles will be enforced and establishes the process for amendment to the Articles of Confederation.
The authority of the government established by the Articles rests in the pledge of all of the delegates to respect the union of thirteen states forever. This forces each individual state to rely on the honor of each of the other states to fulfill their mutual commitments. This reflects a notion similar to the "friendship" promise of Article 2, which had already been demonstrated to be ineffective.
The farther removed the states felt from the threat of war, the less they cared about honoring their pledge to abide by the Articles. In the absence of a strong and coercive power to force states into compliance, states failed to send delegates to Congress, were delinquent on contributions to the general treasury, negligent regarding the matters of foreign commerce, and eager to take power into their own hands. When the need for mutual defense was removed, there seemed to be little need for a central government whose authorization solely covered things related to the common defense.
The significance of this portion of the Articles of Confederation lies not only in demonstrating the weakness of the government from 1781-1789, but also because it provided the means through which the Articles could be revised and the U.S. Constitution could be formed.