WASHINGTON -- Thirty years ago, the last U.S. helicopter lifted off the roof of the U.S. Embassy in Saigon, South Vietnam, marking the official end of the Vietnam War.
The decade-long conflict left 58,000 Americans and an estimated three million Vietnamese dead, and for the next two decades, relations between the United States and the Socialist Republic of Vietnam remained at an impasse.
But 30 years after the war's end, the two countries have reached an unprecedented level of cooperation, U.S. Ambassador to Vietnam Michael Marine told participants at the March 17, Texas Tech 5th Triennial Vietnam Symposium in Lubbock, Texas.
This cooperation extends to security, trade and investment, health, education and culture.
Marine delivered his assessment two weeks before the frigate USS Gary arrived in Ho Chi Minh City for a five-day port call, the third Navy ship to visit Vietnam since the war's end.
The visit marked the 10th anniversary of the normalization of diplomatic relations between the two countries and a warming of military relations between the former foes.
"Now we must put aside the past, and I think we should look forward to the future," Vietnamese Col. Bui Van Nga told the Associated Press during the frigate's visit.
Marine said the United States and Vietnam are putting their differences aside to find common ground in a wide range of issues, including counter-terrorism and regional stability.
"Vietnam and the United States stand together in opposition to the global scourge of terrorism," Marine said, noting that Vietnam has become an active participant in regional counter-terrorism efforts.
Vietnam also shares U.S. opposition to the development and spread of weapons of mass destruction, he said.
As a member of the International Atomic Energy Agency's Board of Governors, Vietnam has publicly called on North Korea to honor its commitment to give up its nuclear-weapons program. "This is of no small significance considering the traditionally close ties between Hanoi and Pyongyang," Marine said.
"Both countries (the United States and Vietnam) desire peace in the Asia-Pacific region and believe that there can be no economic growth and prosperity without a stable security environment," he said. The two countries also share a mutual interest in seeing that strong regional institutions address security challenges, such as international crime, drugs and environmental threats, he said.
A bilateral agreement signed by the two countries last year lends American expertise to Vietnamese law enforcement agents working to stem the flow of drugs into and through Vietnam, Marine said.
"We are hopeful that by building bridges this way, we will be able in the future to expand our cooperation to include more direct cooperative efforts to shut down drug traffickers and other criminal organizations," he said.
But as the two countries look toward a more cooperative future, Marine said, they're helping heal old wounds by working together to find answers to the fate of missing service members in Vietnam, including 1,800 from the United States.
"As we mark the 30th anniversary of the end of the war, we must not forget those on both sides who made the ultimate sacrifice during the terrible conflict," he said. "The best way to do this is to remain steadfast in our efforts to achieve the fullest possible accounting of our missing personnel from the Indochina conflict."
Cooperation in this endeavor enabled the United States and Vietnam to move relations forward on other fronts and remain a top priority, he said.
Marine said he regularly urges the Vietnamese government to maintain its cooperation and to take concrete steps to allow full access to all archival records, renewed joint activities in the Central Highlands, and a concerted effort to conduct underwater activities.
"Right now, there are teams spread out across Vietnam conducting investigations and recovery activities," he said. He referred to five recovery teams, two research and investigative teams and an investigation team from the Joint POW/MIA Accounting Command that deployed to Vietnam in early March.
The Defense Department announced the most recent success in this effort April 12. Two Army officers missing from the Vietnam War since 1971, Col. Sheldon Burnett and Chief Warrant Officer Randolph Ard, were positively identified and their remains were returned to their families for burial.
Four former North Vietnamese soldiers were instrumental in identifying the site where the two officers' OH-58A Kiowa helicopter went down near the Laos border, defense officials said.
"I want to thank the dedicated men and women -- both American and Vietnamese -- who work so hard to find answers for the loved ones of these soldiers," Marine said of the overall POW/MIA recovery initiative.
As these efforts advance, Marine acknowledged, areas remain in which the United States and Vietnam still don't see eye-to-eye, including Vietnam's human rights record. He vowed that the United States would continue pushing Vietnam to improve on progress slowly being made.
But these differences aside, Marine said, the two countries have come a long way since the fall of Saigon 30 years ago and the reestablishment of diplomatic relations just a decade ago.
"When one considers how far apart the United States and Vietnam once were, how implacably against each other we were -- and it wasn't that long ago -- I believe it's a testament to the efforts in both countries to build bridges, foster communication and create an atmosphere of trust and understanding," he said. "I can assure you that these efforts will continue."