Piling on * Navies guard shipping/supply lines. This is true for war time, but it is also true for peace time. * Navies can disrupt enemy supply lines. Supp

Piling on * Navies guard shipping/supply lines. This is true for war time, but it is also true for peace time. * Navies can disrupt enemy supply lines. Supply lines are critical in any prolonged conflict. * Air superiority remains an important aspect of war. We need places near the theater of war to operate aircraft from. An aircraft carrier essentially means we can place an airbase anywhere in the world. This is a more dynamic than limiting ourself to just allies that give us land to build bases. * Armies often use their navy to secure critical resources needed for the war effort, and guard supply lines extracting those resources. Oil, minerals, food, etc. If we increase our industrial capacity during a war we will need to increase our raw material input, at a time when former trading partners might stop selling to us.