War usually brought about inventions and innovations that were later widely used for civilian use (via USA Today). For example, the built-in map applications on our mobile phones that use GPS to help us navigate towns were originally developed by the US Department of Defense in the 1960s. The jeep you drive to your GPS navigation destination was invented during World War II when the Army "needed a light reconnaissance vehicle." 

The same is true for some everyday commercial products that are now ubiquitous. One of them is the Coca-Cola aluminum can, which first appeared at the end of the Second World War. When the conflict began in 1941, Robert Woodruff, then president of The Coca-Cola Company, made the supply of soda to the military a top priority. He issued a directive, “Ensure that everyone in uniform can get a bottle of Coca-Cola for 5 cents, no matter where he is, no matter how much the company spends.”

Even U.S. Army General Dwight D. Eisenhower was aware of the potential impact on morale. He contacted Coca-Cola executives and urged them to establish bottling plants overseas, according to Coffee or Die Magazine, to distribute soda to the military.

As an iconic symbol of the United States, soldiers not only like to drink the sweet drink itself, but also often regard it as a patriotic drink (via Coffee or Die). According to USO, it is seen as a connection with the family and the country, so important that the Coca-Cola Company is “not subject to the same sugar ration restrictions as the public.”

Coca-Cola did not miss any marketing opportunities, and later used these emotions in advertising campaigns. Coca-Cola derives pull-top cans, so they can be "shipped to overseas armed forces" (via Mental Floss). This idea is pragmatic enough, but “the materials needed were rationed during World War II, and the company could not produce them for the troops until the end of the conflict.” It was not until 1960 that aluminum Coca-Cola cans were introduced to the public, this time more for reasons Convenient but not necessary.

Interestingly, the original can design depicted "the outline of a Coke bottle so that customers would not be confused" (from Insider). It seems that people are adapting well.