Which national power instrument is commonly associated with defense and military operations?

The national power instrument that is commonly associated with defense and military operations is the military. This encompasses all aspects of a nation's armed forces, including their organization, training, readiness, and the strategic deployment of military assets. The military serves as a direct means to protect a nation's sovereignty, deter potential aggressors, and project power on a global scale when necessary.

In the context of national security strategy, the military is often the foremost instrument that directly engages in armed conflict or responds to threats against a nation. It is equipped and designed for combat, which distinguishes it from other instruments of national power that might involve negotiation, economic sanctions, or diplomatic efforts. The military's capability to defend a nation and engage in various operations — from humanitarian assistance to full-scale warfare — emphasizes its central role in maintaining peace and security.