By David Hoekman

Yesterday was Dec. 7, which for people of a certain age in the U.S. means only one thing: Pearl Harbor Day.

The Japanese attack on U.S. military bases at Pearl Harbor in Hawaii on Dec. 7, 1941, brought the U.S. into World War II.

Seventy years later, U.S. citizens routinely visit Japan and Germany. Such tours would have been unthinkable in those dark days after Dec. 7, 1941.

Here's a video about Germany:

Two recent emails reminded me that tourism in Vietnam — hardly a priority during the conflict there in the 1960s and 1970s — is now a big thing.

The first email came from Active Journeys, an adventure tour operator based in Toronto. Under the subject line of “Vibrant Vietnam,” the operator notes its upcoming April departure includes not only “incredible biking in the country, kayaking in Halong Bay, but also trekking in Sapa, away from the maddening crowds.”

Later that same day I received an email from Indochina Incentive & Cruise, a tour operator in Ho Chi Minh City (formerly Saigon), Vietnam, for inbound travel professionals. The company’s tagline is “Escape to the Orient, discover Indochina countries of Vietnam, Thailand, Cambodia, Laos and Myanmar.” They want to share the “astounding grandeur of bygone civilizations.”

It’s amazing to me that a mere 30-some years after the U.S. pulled out of Vietnam following a bitter conflict, Vietnam is a vibrant tourist destination. And Americans visit Vietnam.

But I should not be surprised.

Attitudes change with the passage of time. Plus, a couple of new generations have joined the ranks of travelers since the Vietnam War ended. Vietnam does not hold negative connotations for them.

The number of foreign tourists visiting Vietnam in the first 11 months of 2011 reached more than 5.3 million, a year-on-year increase of 15.9 percent, the Vietnam General Statistics Office recently reported.

Of the total, the number of foreign tourists visiting Vietnam for recreational purposes amounted to more than 3.2 million, up 13 percent. Those who came for business and to visit relatives were 887,000 and 889,000 arrivals, respectively.

Over the past 11 months, almost all markets saw increases in the number of foreign tourists to Vietnam. China topped the list with 1.24 million arrivals, up 49 percent. The next were the Republic of Korea with more than 473,000 arrivals (up 5.1 percent), Japan with 425,600 (up 6.8 percent), the U.S. with 398,700 (up 0.8 percent) and Cambodia with 376,400 (up 6.1 percent).

I think today it would be a tough sell to get Americans to buy a leisure tour of Iraq or Afghanistan — if such tours were even available. But if past events are any indication, in the future tours with U.S. travelers will go to both countries.