The cartoon is MOST CLOSELY associated with the controversy over the Watergate affair.
Iranian hostage standoff.
war on drugs.
energy crisis of the late 1970s.

answer; ///i believe that the correct answer is refrigerants,(like r12) and aerosol

the mongolian invasion of china and central asia resulted in a disruption of the silk road as the chinese garrisons lost support from the chinese kingdoms which fell under the mongols. however, as the mongols established a formal dynasty in china, the successors of genghis khan restored the garrisons along the silk road allowing the safe travel caravans again.

it refers to race, i am pretty sure this was a popular term in nazi germany or something.