Don't confuse oyster shell with grit. Grit is insoluble. It stays in the gizzard and it's used to grind food. Oyster shell dissolves in the gut and its job is to add calcium to the diet of laying hens.
Kennedy's strategy of flexible response, managed by Robert McNamara, was aimed to reduce the possibility of war by miscalculation. Kennedy's administration contributed to the peaceful resolution of the Cuban Missile Crisis and refrained from further escalation of the 1961 Berlin Crisis.everal of them were from the foreign policy think tanks. Kennedy had been interested in the issues of war and peace since his youth. In his inaugural address Kennedy encapsulated his Cold War stance as following: Let us never negotiate out of fear. But let us never fear to negotiate.
To prevent that from happening, the United States adopted a new national policy of hemisphere defense. Between 1939 and 1942 the Army played a key role in executing this policy. The achievement of substantial security within the hemisphere permitted the United States to concentrate on the offensive soon after the Japanese attacks on Oahu and Luzon plunged the nation into open war in December 1941.