U.S. Secretary of State John Kerry (R) visits the village of Kien Vang along the Mekong River Delta, Vietnam, Dec. 15, 2013.
U.S. Secretary of State John Kerry (R) visits the village of Kien Vang along the Mekong River Delta, Vietnam, Dec. 15, 2013.

Three high-profile current and former U.S. public servants who fought in the Vietnam War are reflecting on the conflict, while casting an eye on the present and the future.

In a joint op-ed Tuesday in the New York Times, Secretary of State John Kerry, Senator John McCain and former Senator Bob Kerrey, wrote as the U.S. strengthens relations with Vietnam, it is important to remember the lessons learned from the war that claimed the lives of more than 58,000 American and nearly one million Vietnamese.

Although there are "few easy answers" to questions about the lessons, they said "we must never again confuse a war with the warriors."  American veterans "deserve our deepest respect, gratitude and support whenever and wherever they served," they added, an apparent reference to the derision Vietnam veterans faced when they returned home from the controversial war in the 1960's and 1970's.

They also cited the need for leaders "to be honest" with Congress and the American public about military plans, a declaration that comes decades after the first U.S. combat troops deployed to Vietnam were described as "flood relief."

Exercising "humility in assuming knowledge about foreign cultures" and overcoming "seemingly unbridgeable differences," which are evident this week in Vietnam, are among the other lessons the United States has learned from the war, which raged in Southeast Asia from 1955 to 1975.

FILE - U.S. Sen. John McCain, R-Ariz, is seen duri
FILE - U.S. Sen. John McCain, R-Ariz, is seen during a tour of Hoa Lo Prison site, Hanoi, April 8, 2009. The photo behind McCain is that the Hanoi army and people pull out McCain out of Truc Back Lake on Oct. 26, 1967 after his plane was shot down.

Kerry, McCain and Kerrey are proud of the contributions they made toward the resumption of normal diplomatic relations 20 years ago between the U.S. and Vietnam.  For example, fewer than 60,000 Americans visited Vietnam annually 20 years ago, compared to nearly one half million today, and bilateral trade with Vietnam is nearly 100 times the $450 million dollar figure of 20 years ago.

As President Barak Obama visits Vietnam this week, the three veterans describe his relationship building efforts as "wide-ranging," covering issues from security, trade, investment, the environment and "freedom of religion and human rights."

Looking ahead, they wrote, "mutual interests" and "natural affinities" such as family ties and a "fierce desire for freedom" will help strengthen ties between the two countries.

John Kerry was a naval officer in Vietnam.  McCain was a naval officers and a prisoner of war in North Vietnam for five and 1/2 years.  Bob Kerrey was awarded the Medal of Honor for his service as a Navy SEAL in Vietnam.