Leandro Aragoncillo, 48, apologized in court for his actions and said he was just trying to help bring Filipinos out of poverty.
"I never intended to cause harm or injury to the United States," he said.
Aragoncillo worked as a military aide to vice presidents Al Gore and Dick Cheney starting in the late 1990s before joining the FBI as a civilian employee at Fort Monmouth.
He pleaded guilty in May 2006 to four charges. The most serious charge, conspiracy to transmit national defense information, can carry the death penalty, but under his plea agreement, Aragoncillo faced a maximum of 20 years in prison.
U.S. District Judge William H. Walls said he believed that Aragoncillo, a naturalized U.S. citizen born in the Philippines, did not mean to hurt the United States. But he said, "There's no doubt you did betray a position of trust that very few people are privileged to occupy."
Judge Walls also fined Aragoncillo $40,000. There is no parole in the federal system, and Aragoncillo can be expected to serve nearly the entire sentence except for potential good-inmate credits.
"Those charged with protecting the nation have a special responsibility to maintain their oath of loyalty to the United States," said Assistant Attorney General Wainstein. "As a former U.S. Marine and FBI analyst, Aragoncillo betrayed that oath, violated our espionage laws, and now must suffer the consequences of his actions."
A co-conspirator, former Philippine National Police officer Michael Ray Aquino, was sentenced Tuesday to six years and four months in prison. He pleaded guilty last year in a deal that spared him the possibility of a life sentence. Both men were arrested in September 2005.
The plot involved the theft of classified national defense documents from the White House and the FBI.
Aquino, 41, admitted possessing secret documents containing information on the United States' confidential intelligence sources and methods, as well as information on terrorist threats to U.S. military personnel in the Philippines.
Recipients of the information included former Philippines President Joseph Estrada, who was ousted six years ago; Panilo Lacson, an opposition senator; and former House Speaker Arnulfo Fuentebella, according to court documents. Estrada and Lacson have acknowledged receiving information from Aquino or Aragoncillo, but deny any wrongdoing.
Prosecutors said Aragoncillo was recruited in 2000 by opposition forces and began working with Aquino in early 2005. Aragoncillo admitted passing information to Aquino and opposition politicians in his homeland who wanted to oust Philippine President Gloria Macapagal Arroyo.
Aquino was once a senior officer under Lacson in the Philippines National Police. He fled to the United States to escape murder charges in 2001 and lived with his wife and son in New York City. After serving his prison term, he is likely to be deported.