Running for president in 1968, Richard Nixon made a bold promise: He would end the draft.
And he did. The Pentagon switched to an "all-volunteer force."
But recruiting and retaining volunteers costs more. That, paired with pressure to reduce defense spending, made reliance on the Army Reserve and National Guard essential.
Unless mobilized, reserves can be maintained far more cheaply than active forces. President Nixon's Army chief of staff, Gen. Creighton Abrams, made partnership with the National Guard the centerpiece of plans for the post-Vietnam Army.