From the early 1960s until 1975, Vietnam and the United States were embroiled in one of the late 20th century's most disastrous conflicts. The Vietnam War — sometimes called the "American War" in Vietnam — took a terrible toll on both countries. More than 58,000 U.S. service members and hundreds of thousands of Vietnamese civilians died in the war. And while the eventual fall of Saigon — a huge defeat for the United States and its South Vietnamese allies — ended the war, its (quite literally) poisonous legacy lives on.

You might expect hard feelings to linger as well, but apparently they do not. In a historic move, President Obama lifted a long-standing embargo on sales of lethal arms to Vietnam during a visit to the country this week.

This is only the latest move in political reconciliation between the two countries. Here's a brief rundown:

  • 1994: The United States lifts its trade embargo on Vietnam.
  • 1995: The United States and Vietnam normalize relations.
  • 2000: President Bill Clinton becomes the first U.S. head of state to visit the country since the war. Later, both countries sign a bilateral trade agreement, which paves the way for Vietnam to join the World Trade Organization.
  • 2006: George W. Bush becomes the second consecutive U.S. president to visit Vietnam since the end of the war.
  • 2007: Congress approves "permanent normal trade relations" status for Vietnam.
  • 2015: Obama welcomes Nguyen Phu Trong to the White House. Trong is the first Vietnamese Communist Party leader to visit the Oval Office.

These diplomatic efforts are somewhat mirrored in public opinion polls.

Vietnam has become one of the most U.S.-friendly nations in Asia, if not the world. One recent poll from Pew found that 78 percent of Vietnamese citizens had a favorable view of the United States while 50 percent felt that the United States was the world's leading economic power. Perhaps even more remarkable, given the context, another Pew poll found that 95 percent of Vietnamese felt that people were better off in a free-market economy.

(To be fair, not all polls paint quite as dramatic a picture. Data from Gallup found that 27 percent of Vietnamese residents approved of the leadership of the United States, though only 7 percent disapproved and 66 percent said they either didn't know or didn't want to answer the question.)

There's less data on what Americans think about Vietnam, unfortunately. Gallup has data from 2003 that found 43 percent of Americans had a favorable view of Vietnam while 39 had an unfavorable view (and 18 percent had no opinion). This was an improvement from just three years earlier, when just 36 percent of Americans had a favorable view of Vietnam and 53 had a negative view. Meanwhile, American views on the Vietnam War have remained negative in recent years: Another Gallup poll from 2013 showed that 57 percent of Americans think that sending troops to fight in Vietnam was a mistake.

This isn't always how things go — the persistent anger in South Korea and China over Japan's actions during World War II is evidence of how rancor can linger. So what went differently between the United States and Vietnam? There's no easy answer. It's certainly clear that economic ties between Vietnam and the United States have blossomed since 1994. Trade between the two countries was worth $451 million in 1995. Last year, it was worth $45 billion, with Vietnamese imports to the United States making up the vast majority of that. The signing of the Trans-Pacific Partnership — a free-trade agreement between the United States, Vietnam and 10 other nations — earlier this year may well add to this.

Vietnam is a young nation — the median age is about 29 — with many people born after the end of the Vietnam War. Many probably view these economic relationships as more important than the Cold War politics of more than 40 years ago.

But perhaps the elephant in the room is China, Asia's enormous rising power, one that both Washington and Hanoi are wary of. The same Pew poll that found 78 percent of Vietnamese people had a positive view of the United States found that just 19 percent thought positively of China. Vietnam and China fought a bloody border war in 1979 that is perhaps just as remembered in Vietnam as the "American War." More recently, China's aggressive pursuit of maritime territorial claims has alienated many Vietnamese leaders — who have found themselves willing to look toward old enemies for support.

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