It is, arguably, the saddest day in U.S. military history -- certainly in modern U.S. military history -- the Civil War's Battle of Gettysburg probably is the saddest.

The day:

Sunday, December 7, 1941, a date which will live in infamy, President Franklin D. Roosevelt said at the time.

And it has. Seventy years ago today, on Sunday, December 7, 1941, the United States naval base at Pearl Harbor, was, as FDR put it, suddenly and deliberately attacked, by the Empire of Japan.

2,402 U.S. Armed Forces Killed in Attack on Pearl Harbor

The attack triggered the U.S.'s entrance into World War II, with the U.S. declaring war on Japan on Dec. 8. The U.S. did not declare war on Japan's Axis partner Nazi Germany until Adolf Hitler declared war on the U.S. three days later.

The U.S. losses at Pearl Harbor were enormous: 2,402 members of the armed forces were killed, and 1,282 were wounded. All eight U.S. battleships were damaged, and four were sunk. All but two ships, however, were raised, repaired and returned to service later in the war.

Imperial Japan also sank or damaged three cruisers, three destroyers, an anti-aircraft ship and one minelayer. Japan lost 29 of its 353 invading aircraft, and 65 Japanese servicemen were killed or wounded.

The U.S. Arizona, one of the battleships sunk that was not raised, marks the resting place of 1,102 of the 1,177 sailors killed during the Pearl Harbor attack, and now a national memorial site; it was declared a National Historic Landmark on May 5, 1989.

U.S.S. Arizona Memorial

To say that a trip to Pearl Harbor and the U.S.S. Arizona Memorial to pay one's respect to all who lost their lives on that fateful day is a fitting and appropriate experience would be an understatement. At the memorial, one learns that freedom and democracy are not cost-free, and that many have died to keep the United States a nation with a government based on the consent of the governed.

Attendees can also learned about the U.S.'s heroic effort in World War II, in which America, aided by Britain and Russia (then the Soviet Union) defeated the greatest threat to the democracy and the development of nations, the Axis powers of Nazi Germany led by Adolf Hitler, Imperial Japan, and Fascist Italy led by Benito Mussolini.

One counter to the above, sometimes disproportionately voiced by young people, is that they question the need to learn about Pearl Harbor because it's not relevant to my life. It may not appear to be, but what the United States fought against is relevant, if you're a fan of freedom, democracy and government based on the consent of the governed.

Americans should learn about what occurred on Dec. 7, 1941, for the same reason they should learn about what occurred on Sept. 11, 2001 -- each ushered in a new era and reminded the nation of the price that has been paid throughout its history to maintain a free and democratic society.

However, that is not to say that learning about the lesson of Pearl Harbor does not take some effort. The United States, the nation, is a long, long way from the World War II era. In fact, students and young adults learning today about Pearl Harbor (70 years ago) are almost as removed in time from World War II as students in 1941 were from learning about the Civil War (76 years).

But learning about the lessons of Pearl Harbor and Gettysburg is a very small price to pay, compared to what those in battle paid in 1941 and in 1863.

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