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.
Vietnamization was a policy of the Richard Nixon administration during the Vietnam War to end the U.S.' involvement in the war and expand, equip, and train South Vietnam's forces and assign to them an ever-increasing combat role, at the same time steadily reducing the number of U.S. combat troops. From wikipedia.