By MICHAEL MORELLA

On Dec. 7, 1941, radios buzzed with the news that several hundred Japanese planes attacked a U.S. naval base at Pearl Harbor in Hawaii, killing more than 2,400 Americans as well as damaging or destroying eight Navy battleships and more than 100 planes. Though it would be some time before people learned the full scope of the damage, within days a once-distant war in Europe and the Pacific became a central part of life in the United States, affecting politics, business, media, and entertainment. In his new book, December 1941: 31 Days That Changed America and Saved the World, Craig Shirley offers a day-by-day chronicle of the full month and recounts Pearl Harbor’s political, economic, and cultural implications as they happen. Shirley, the president and CEO of a Washington, D.C., area public relations firm and author of two books on Ronald Reagan, recently spoke with U.S. News about how Americans responded to Pearl Harbor in 1941 and what its legacy is 70 years later. Excerpts:

Why did you decide to recount all of December 1941?

There have been many fine books on Pearl Harbor. But nobody has ever done a book about the month of December 1941 and the radical changes that happened in this country between the 1st and the 31st. I thought it would be fun for me and fun for the reader to see what America goes through in those 31 days.

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What was life like for Americans in early December 1941?

On Dec. 6, 1941—it was a Saturday—Americans were listening to the radio, as all Americans did at that time. They were listening to local programming—news, farm reports, game shows, children’s [programs], music contests, talent shows, things like that. In those days, the average American went to the movies twice a week. And the movies that they may have been seeing that night would have been Citizen Kane or The Maltese Falcon or Dumbo. But they weren’t thinking about war. They really weren’t thinking about war in the Pacific—that was the farthest thing from their minds. They were thinking about the war in Europe, but they weren’t thinking about their involvement in the war in Europe.

How were diplomatic relations with Japan?

Extremely tense. The Japanese had become so much more militaristic over the previous 10 years. We were feverishly negotiating. The Japanese broke off diplomatic relations with the United States, but nobody interpreted that as a prelude to war.

What changed after the attack on Pearl Harbor?

Within a matter of hours of the attack, America is moving quickly to get on a war footing. American attitudes about the war change radically, [as do] American attitudes about the economy, about giving to the war. The war is not part of the culture; the war is the culture. Everything is viewed through the prism of the war effort.

[Read: Barack Obama Commemorates Pearl Harbor Attack]

How so?

Virtually all movies have a war theme. Virtually everybody gets up in the morning thinking, what can I do to help the war effort? Children are doing scrap drives, paper drives, metal drives, rubber drives, grease drives. Nobody has a new car for a long time because Detroit stops making new cars. There are stricter regulations on travel for a lot of people, especially Japanese-Americans, German-Americans, Italian-Americans. San Francisco and Los Angeles are under constant rumors of being bombed.

What did contemporary leaders learn from the attack on Pearl Harbor?

That the world is a very complex place. I don’t think it was American weakness that put us into World War II; duplicity by the Japanese is what put us into the Pacific war and arrogance by Nazi Germany put us into the European war.

Seventy years after entering World War II, the United States is finishing a war in Iraq. Do you think that is the right move?

Yes. A lesson that I think has been lost on current American civilian leaders is that [Gen. Douglas MacArthur] knew that Caesar and Napoleon and others had failed as conquerors of occupied countries because their policies were so harsh. He didn’t make that mistake in Japan. I think we’ve done a good job in Iraq. But it remains to be seen.

[Read the U.S. News debate: Was The Iraq War Worth It?]

What will surprise readers most about this book?

How quickly and actually, in a magnificent sort of way, we become the arsenal of democracy. Probably because of all the competing interests of today it could never happen. In December [1941], the Office of Production Management says to Detroit, says to the Big Three automakers, “You’re no longer going to build cars, you’re going to start building airplanes.” They’re doing this in less than a month out of fabricated auto parts. That was happening across America, across industry. The outpouring from American people and the faith in their government and in their military and in their president, which was bipartisan, really did exist.

• http://www.usnews.com/opinion/articles/2012/01/06/how-america-changed-after-pearl-harbor_print.html