Final answer:
The US Constitution provides for the common defense through the power of Congress to raise armies and maintain a navy, as well as allowing states to form militias.
Step-by-step explanation:
The US Constitution provides for the common defense of the country through various means:
- By granting Congress the power to raise and support armies, as stated in Section 8 Clause 12.
- By allowing states to form their militias, as mentioned in Section 8 Clause 15.
- By empowering Congress to provide and maintain a navy, stated in Section 8 Clause 13.
These provisions ensure that the nation has the ability to protect itself from external threats.