Why is the setting important in the story "The Machine That Won the War"? What would the story be like without the settings that the author created?
The setting of this story is sometime in the future. Asimov wisely did not put a date into his story. That allows the story to take place in the future for a very long time. It's funny to watch an old movie like 2001: A Space Odyssey because here we are in 2016, and our ability to travel through space is nothing like predicted in the movie. This story was first published in 1961, but it still reads like a look into our current future. We use computers a lot, but nobody assumes that a computer can make war decisions better than people... Yet.
The setting of the story is also set soon after the war with the Denebians has ended. Readers discover later in the story that the war has been going on for many years, so placing the story after the war allows the three main characters to plausibly be together discussing Multivac. The war detail is also important because it shows just how much humanity has come to depend on computers and technology. Supposedly, a machine is more capable than humans of making life or death decisions regarding millions of people. That shows a tremendous amount of faith in the technology.
Without the war details as part of the setting, I do not think this story would be as powerful. Having a machine make decisions about who to save and who to kill is critical to showing readers how much faith humans are beginning to put in machines. If Multivac was only making decisions about how to better adjust traffic patterns, the story wouldn't be quite the warning that it is to readers in its current state.