Interesting comparison of the Reagan policy verses Bush Policy. Both very similar in design.
Perhaps a comparative study of bombing Libya (Terrorism) verses Aghanistan (harboring/promoting terrorism) vs Clinton’s straying from a first strike capability to being attacked first and then responding.
Iraq and Iran, for better or worse, will be classified under the same framework. A terrorist state possessing WMDs or nuclear capabilities.
However, whereas Reagan's policies were primarily focused on meeting the Soviets where they went (via direct action and support of democratic governments/guerrillas), the Bush Doctrine focuses on eliminating threats before they mature. IMHO, that is a departure from previous doctrines.