Of more direct and immediate bearing upon our national security are the changes wrought in the strategic potential of the Pacific Ocean in the course of the past war. Prior thereto the western strategic frontier of the United States lay on the littoral line of the Americas, with an exposed island salient extending out through Hawaii, Midway, and Guam to the Philippines. That salient proved not an outpost of strength but an avenue of weakness along which the enemy could and did attack.
The Pacific was a potential area of advance for any predatory force intent upon striking at the bordering land areas. All this was changed by our Pacific victory. Our strategic frontier then shifted to embrace the entire Pacific Ocean, which became a vast moat to protect us as long as we held it. Indeed, it acts as a protective shield for all of the Americas and all free lands of the Pacific Ocean area. We control it to the shores of Asia by a chain of islands extending in an arc from the Aleutians to the Mariannas held by us and our free allies. From this island chain we can dominate with sea and air power every Asiatic port from Vladivostok to Singapore -- with sea and air power every port, as I said, from Vladivostok to Singapore -- and prevent any hostile movement into the Pacific.