Why did president kennedy change the focus on american military tactics in the early 1960s?

i do not know if this question has options, but a main impact of the federal reserve act of 1913, which created the federal reserve bank, was the international use of the u.s. dollar, which soon became the world's leading currency - particularly during world war i, since many nations around the world asked the united states for money.

i believe george gallup used a poll in 1936