The term common defense in the Preamble to the U.S. Constitution refers to the collective protection and security of all the states and their citizens. It emphasizes the importance of a unified approach to national security, ensuring that the country is safeguarded against external threats and internal conflicts.
The framers of the Constitution recognized that individual states, acting alone, might not be able to effectively defend themselves against larger or more powerful adversaries. By including common defense in the Preamble, they highlighted the need for a strong, centralized federal government capable of coordinating defense efforts and maintaining a standing army and navy.
This concept also underscores the idea of mutual support among the states. It implies that the security of one state is interconnected with the security of all others, and that the federal government has a responsibility to protect the entire nation. The principle of common defense is further reflected in various constitutional provisions, such as the power of Congress to declare war, raise and support armies, and provide for a navy.
In summary, common defense in the Preamble signifies the commitment of the United States to protect its citizens and territories through a unified and coordinated national defense strategy.