The U.S. was involved in a lot of wars in the 20th century. World War I and World War II, Vietnam, Bosnia, and Iraq...

But wait. Aren't we forgetting something? Like another war? Ah yes, now that you mention it, we also fought a three-year war in Korea from 1950 to 1953.

Yes, just five years after the enormous conflict of WWII, the U.S. was fighting another war. But the Korean War was very different from ol' WWII. The fighting was contained to the small space of Korea, which most Americans couldn't find on a map.

Heck, they couldn't find their own houses. How could they find Korea? So, how did we end up in a war in Korea?

• After WWII, Korea was divided by the Allies into zones, just like Germany had been.
• The Soviets occupied North Korea and the U.S. occupied South Korea.
• Unlike East or West Germany, the two Koreas weren't content to live apart. Both wanted to unify, but each wanted to unify on its own terms. (Hint: that's not how you do unity.)
• North Korea couldn't wait for South Korea to change its mind about becoming a communist state, so it attacked South Korea in 1950. The United States-led international force that swung into action pushed North Korea way back, and we were all set to win a quick victory and create a unified, democratic Korea.

And then, in a puff of orange smoke, wicked old communist China turned up and ruined everything. With Chinese forces fighting with the North Koreans, the Korean War lasted three years. 36,000 Americans, 3,000 UN soldiers, about 150,000 Chinese soldiers, and—worst of all—about 3 million Korean civilians were killed.

It's hard to believe a war this costly could be so invisible. Part of the reason was that it didn't have a traditional ending with a winner and a loser. The war ended with a ceasefire agreement in 1953 and Korea was left exactly where it started, divided at the 38th parallel. 

America didn't win. We didn't lose. What we did do was forget about the unsatisfactory Korean War.

Sandwiched between the storied glory of the Second World War and the televised tragedy of Vietnam, the 1950 to 1953 war in Korea—the first hot spot of the Cold War—today often goes unremembered. The 50th anniversary of the conflict came and went from 2000 to 2003 with little fanfare. 

In 2004, when author David Halberstam walked into the Key West, Florida public library while researching a book on the Korean War, he found its shelves held 88 books on Vietnam and only four on Korea.²

But the Korean War shouldn't be forgotten. In one sense, it's not even over yet. It has now been nearly 20 years since the Berlin Wall fell and the Soviet Union collapsed. Vietnam has long since made peace with the United States and entered the capitalist marketplace. But Korea still remains divided along the 38th parallel, with communist and anticommunist forces—including Americans—staring each other down every day across the no man's land of the demilitarized border.

The Cold War may be over, but North Korea still has a totalitarian communist government—and the country's recent development of a nuclear weapons program makes it a major threat to the United States, even today. It's impossible to understand the ongoing clashes between the United States and North Korea without understanding the context of a 50-year-old conflict.

Understanding the Korean War, which ended in frustrating stalemate, is also critical to understanding the even more disastrous quagmire that developed the next time American soldiers went into battle against a communist foe in Asia: the Vietnam War. As historian Richard Whelan has argued, "In many terrible ways, Korea was a dress rehearsal for Vietnam. It should, on the contrary, have provided a warning clear and potent enough to avert the later exercise in savagery and futility."³

But American leaders in the 1960s didn't learn the history lesson of the Korean War, blundering into a great catastrophe because of it. Don't make the same mistake.