Thomas Kimmel Jr. is on a World War II mission, although he is too young to have fought in any of its battles. This former Navy officer, who served on three warships in Vietnam, is seeking to restore the four-star admiral rank of his grandfather, Admiral Husband Kimmel, who commanded the Pacific fleet during the Japanese attack on Pearl Harbor.

Relieved of his command after the devastating assault on December 7, 1941, the elder Kimmel remained haunted by the attack until his death in 1968: “You could not talk to the man for two minutes before Pearl Harbor came up,” Thomas Kimmel recalled of his grandfather, an imposing figure with a Kentucky twang.

A commission appointed by President Roosevelt in 1941 leveled a charge of dereliction of duty. But the Naval Court of Inquiry, the only one of the nine investigations during Admiral Kimmel’s lifetime in which he was allowed to call and cross-examine witnesses, exonerated him, finding no evidence to support such a charge.

The public affairs officer for the Naval Historical Center, Jack Green, said historians’ opinions about Admiral Kimmel have varied. An emeritus professor at the University of Florida, Michael Gannon, said Admiral Kimmel was a scapegoat for incompetence in Washington. Mr. Kimmel said his grandfather and General Walter Short, who was the senior Army commander in charge of protecting Pearl Harbor, were not provided with crucial information, including intercepted Japanese diplomatic and spy communications decoded in Washington prior to the attack. Admiral Kimmel was kept “out of the loop,” his grandson said.

But Mr. Green, who was the Department of Defense’s historical adviser to the 2001 film “Pearl Harbor,” said while there was information that Admiral Kimmel should have been given, the admiral possessed enough information to have been more “proactive.”

Mr. Gannon, author of “Pearl Harbor Betrayed: The True Story of a Man and a Nation Under Attack,” said he disagreed. “Proactive, the man was,” he said. Among other examples, Mr. Gannon said Admiral Kimmel even violated rules to have ammunition taken out of lockers and placed with the guns to respond more quickly.

Thirty-three four-star admirals, two former chairmen of the Joint Chiefs of Staff, a former director of intelligence, the Pearl Harbor Survivors Association, and others have subsequently supported the effort to have the ranks of Admiral Kimmel and General Short restored. In an amendment to a spending bill, Congress in 2000 voted to recommend this posthumous restoration of rank, which has lacked presidential action.

Admiral Kimmel’s grandson is following in the footsteps of relatives such as his attorney uncle and his father, a former Navy captain, who assiduously worked on the matter. Thomas Kimmel’s own investigative skills were honed while serving for more than a quarter-century as an FBI agent, fighting organized crime in Cleveland and heading the Labor Racketeering Unit at the FBI headquarters. Today he will give a talk in Brooklyn Heights, “The Story Within the Pearl Harbor Story,” which will shine light on little-examined documents showing the role of the FBI in the matter.

Over the years, the Kimmel family has been immersed in military service, almost enough to form its own squadron: Nine have graduated from service academies, including six from the Navy. Mr. Kimmel’s fourth great-grandfather, a Quaker named Herman Husband, stirred up a nest of hornets that led to the Battle of Alamance in 1771, a prelude to the Revolutionary War, before moving to Pennsylvania, where he helped foment the Whiskey Rebellion.

Mr. Kimmel said that while Husband had been accused of starting both the Revolutionary War and the Whiskey Rebellion, Admiral Kimmel was accused from the well of the House of Representatives by the chairman of the House Appropriations Committee, Clarence Cannon, of failing to prevent not only World War II, but the Cold War as well. Mr. Kimmel said the FBI had fed information to Cannon to lead him to that conclusion.

During the first attack on the World Trade Center in 1993, Mr. Kimmel was the assistant agent in charge of the Philadelphia FBI division heading the foreign counterintelligence and terrorism programs. He said Pearl Harbor has resonance for America after the attacks of September 11, 2001, and that one unlearned lesson was that governmental agencies such as the CIA and FBI need to share information better.

But some improvements have been made, he said. While in the aftermath of September 11 both the head of the FBI, Louis Freeh, and the director of intelligence, George Tenet, testified, neither the head of the FBI, J. Edgar Hoover, nor the head of the Office of the Coordinator of Information, William Donovan, ever testified at any of the Pearl Harbor investigations, Mr. Kimmel said.

gshapiro@nysun.com