Seventy years ago this month, the Japanese attacked Pearl Harbor and brought America into a war that had begun in Europe in 1939.

In his masterful new book “December 1941: 31 Days That Changed America and Saved the World,” Craig Shirley takes readers back to a very different America. Through hundreds of stories and advertisements culled from newspapers, Shirley not only transports us back to that tumultuous time, but reminds this generation that denial about an enemy’s intentions can have grave consequences.

Each chapter in the book deals with a single day of December 1941. We go to the movies with Clark Gable and Betty Grable, view the “cafe society” of New York, and listen to radio stars like Jack Benny and Walter Winchell, the acerbic columnist and powerful radio gossip.

The major players are all here: President Franklin D. Roosevelt, Secretary of State Cordell Hull, Winston Churchill and countless generals and admirals, as well as other military and political figures familiar to any student of history. But, depending on your age, the real stars were our parents, grandparents and great-grandparents. After the Dec. 7 attack, Americans rallied around a single patriotic cause – the defeat of fascism and the salvation of Western democracy, an effort similar to the national unity displayed following the terrorists attacks of Sept. 11. The unity of 70 years ago, however, lasted a lot longer. Record numbers enlisted in the military. Many isolationists became interventionists. Even some conscientious objectors announced, in light of the Japanese sneak attack, that they could no longer remain apart from what was rightly cast as a fight for America’s very survival. Though they refused to kill, many served vital roles in the war effort as noncombatants.

Amid the deeply human and moving stories of family loss are some funny accounts of government stupidity. Shirley writes that government polltakers in the 1940 census asked American men and women how many individual articles of clothing they owned and how many they purchased each year. The Los Angeles Times reported, “Census Bureau officials declare they have found the explanation for cluttered clothing closets in the American home; people just buy more than they need.”

Intrusive government is not a modern phenomenon.

Concerning Russia, the American left in 1941 was oblivious to the intentions of our supposed “ally.” Shirley writes, “…many on the American left were quite naive about the real nature of the Soviet state. Many liberals and intellectuals, who should have known better, perceived it as a worker’s paradise; it was only after the war that the true horrors of Stalin’s repressive regime truly came to light. The muck-raking journalist, Lincoln Steffens, famously asserted, after visiting communist Russia: ‘I have seen the future, and it works’ … Even FDR viewed Stalin as an avuncular fellow with whom he could do business, referring to (him) as ‘Uncle Joe.’ The ugly realities of the gulag would eventually emerge for the entire world to see.”

To those for whom this is familiar territory, it is worth revisiting. For people younger than 70, it is worth discovering. This “greatest generation” was not necessarily braver than other generations; its men and women were simply imbued with a profound sense of duty.

That call to duty is evident in a letter from a young man to his father, which was typical, says Shirley, of the sentiment in December 1941:

“Dear Dad, There is a war on and I am now in it, but that must not be a cause for you to worry. Of course there is danger and there will be more danger to come but if I am to die a soldier’s death, so be it. … You must think of me as doing my duty to God and country. Be brave and show outward pride, that the mite of humanity you helped bring into the world is now a soldier doing his part of defending our great and wonderful country. … You must pray, not only for me and others in the Army, but for the innocent women and children who will have to endure untold suffering from this fight for freedom of religion, speech and democracy. I am not afraid to die for this. … Until then I remain and always, Your Loving Son.”

December 7, 1941 may be a day that “will live in infamy,” but that month, those years, that war revealed an American character still on display in our military today, though it’s somewhat lacking in our civilian population.

© 2011 TRIBUNE MEDIA SERVICES, INC.