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EXCLUSIVE:  The son of the U.S. Air Force pilot who dropped the first atomic bomb in the history of warfare says the Obama administration's decision to send a U.S. delegation to a ceremony in Japan to mark the 65th anniversary of the attack on Hiroshima is an "unsaid apology" and appears to be an attempt to "rewrite history."

Gene Tibbets, son of Brig. Gen. Paul W. Tibbets, Jr., says Friday's visit to Hiroshima by U.S. Ambassador John Roos is an act of contrition that his late father would never have approved.

"It's an unsaid apology," Tibbets, 66, told FoxNews.com from his home in Georgiana, Ala. "Why wouldn't it be?  Why would [Roos] go? It doesn't make any sense.

"I know it's the anniversary, but I don't know what the hell they're trying to do. It needs to be left alone. The war is over."

Tibbets, whose father died in 2007 at the age of 92, said he receives dozens of calls from veterans every year around this time thanking him for his father's service.

"'If it wasn't for your dad, I wouldn't be here,'" Tibbets said many veterans tell him. "This has been going on since he dropped that bomb."

Tibbets said he sees Roos' impending visit -- it will be the first time the U.S. has sent a delegation to the anniversary commemoration in Hiroshima -- as an attempt to revise history.

"It's making the Japanese look like they're the poor people, like they didn't do anything," he said. "They hit Pearl Harbor, they struck us. We didn't slaughter the Japanese -- we stopped the war."

Roughly 140,000 people were killed or died within months after an American B-29 -- nicknamed the Enola Gay -- bombed Hiroshima on Aug. 6, 1945. Three days later, roughly 80,000 people died when the U.S. dropped a second bomb on Nagasaki.  Japan surrendered nine days later, bringing an end to World War II.

White House officials on Wednesday referred calls to the State Department, which did not  respond to several inquiries about how the decision was made or if national veterans organizations were contacted prior to the announcement that a delegation would attend the commemoration.

During Wednesday's daily press briefing, State Department officials defended the visit, saying Roos' attendance at the ceremony "was the right thing to do," spokesman PJ Crowley said.

The ceremony will begin early Friday with the ringing of a bell and the release of doves. Roos visited Hiroshima weeks after he arrived in Tokyo as a U.S. ambassador last year, and the response was generally positive.

Lt. Col. Rob Manning, director of public affairs at the Joint Force Headquarters National Capital Region U.S. Military District of Washington, which oversees ceremonies at Arlington National Cemetery, said Japanese officials are "fairly frequent" visitors to the national site.

"Emperor Hirohito visited the cemetery and placed a wreath at the Tomb of the Unknowns in the early 1970s," Manning wrote in an e-mail. "Most of the more recent prime ministers have also placed wreaths at the Tomb as a part of their official visits to Washington. Service chiefs and ministers of defense also are invited to Washington on official visits and conduct official ceremonies at the Tomb."

In April, Manning said, Prime Minister Naoto Kan, who was Japan's deputy prime minister for finance at the time, placed a wreath at the Tomb and visited sections of Arlington National Cemetery where Iraq and Afghanistan war veterans are buried.

Manning said Gen. Ryoichi Oriki, the Japanese Army's chief of staff, also visited the cemetery and placed a wreath on a grave on June 24.

President Obama is expected to visit Japan in November, and calls have been growing there for him to visit Hiroshima and Nagasaki, since he has spoken of his vision of a nuclear-free world.

Tibbets said he hopes Obama will decide to forgo visiting to the two cities.

"What's his purpose? I don't know what it'd do," Tibbet said. "History is history, the past is the past. You can't change it and I don't know why he'd visit Hiroshima and Nagasaki.

"This all sounds like, 'Oh, we did you wrong.' That's what it sounds like."

Ryan Gallucci, a spokesman for AMVETS, an organization representing more than 180,000 veterans, said his organization supports the decision to send Roos, but he said the visit should not be seen as a conciliatory act.

"Considering how our relationship with Japan has evolved into a peaceful partnership over the years, we support the U.S. decision to send an envoy acknowledging the human toll of WWII," Gallucci said in a statement to FoxNews.com. "To AMVETS, the U.S. visit is an appropriate act of reciprocation for Japan's solidarity over the years, such as last summer's visit to the Punch Bowl National Cemetery (the National Memorial Cemetery of the Pacific) by Emperor Akihito, where he laid a wreath in honor of America's sacrifices in WWII.

"However, in no way should the United States be expected to apologize for its actions, and we hope that this visit will not be misconstrued as an act of contrition."

Paul Schalow, a professor of Japanese at Rutgers University, told FoxNews.com that Japanese media outlets are linking Roos' visit to Obama's desire to rid the world of nuclear weapons.

"They're linking it to Obama's speech in Prague," he said. "They connect Roos being there as proof of interest by the Obama administration to reduce the number of atomic weapons worldwide."

Schalow said Roos' visit appears to "pave the way" for Obama to visit the two cities that were decimated by atomic bombs 65 years ago.

"I imagine the Japanese would be eager to receive a U.S. president," he said. "The real question is the domestic reaction to it. [White House officials] are probably observing reactions of veterans' groups to this official visit by Roos."

Schalow speculated that Roos' visit could be a step toward positioning the U.S. to condemn any future use of atomic weapons, perhaps by North Korea.

"If we show some regret of our own use of the weapon, if it happens again, we're in a moral position to criticize," he said. "As of now, we're not in a position to denounce it."

Kia Tibbets, Gene Tibbets' daughter, said her grandfather would be disappointed with Friday's ceremony if he were alive today.

"Embarrassed might be the word, that the government wasn't backing him up anymore," said Tibbets, 35, of Columbus, Ohio. "But then again, that's politics for you."

The Associated Press contributed to this report.