Final answer:
The significant weakness of the Articles of Confederation was that the central government lacked the power to tax and raise an army.
Step-by-step explanation:
The significant weakness of the Articles of Confederation was that the central government lacked the power to tax and raise an army. Under the Articles, the national government had to rely on the states to provide soldiers and funds for defense. This limited the ability of the central government to effectively protect the country especially at a time when England and Spain still controlled large portions of North America.