sentences:  It was followed by the Eisenhower Doctrine, the Kennedy Doctrine, the Johnson Doctrine, the Nixon Doctrine, and the Carter Doctrine, all of which defined the foreign policy approaches of these respective U.S. presidents on some of the largest global challenges of their presidencies.At least one component of the Reagan Doctrine technically pre-dated the Reagan Presidency.In Afghanistan, the Carter administration began providing limited covert military assistance to Afghanistan's mujahideen in an effort to drive the Soviets out of the nation, or at least raise the military and political cost of the Soviet occupation of Afghanistan.