A former Pentagon analyst has pleaded guilty to passing classified information to pro-Israel lobbyists.
Franklin is co-operating with the prosecution
Larry Franklin said he had been unhappy with aspects of US foreign policy and hoped the lobbyists would use their contacts to get things changed.
Franklin, 58, said he had also given information to an Israeli diplomat, but played down its importance.
He has agreed to help prosecutors, which means his sentence could be reduced when it is decided in January.
Israel has denied any involvement.
Franklin told the Virginia court on Wednesday that he had given defence information to two officials from the American Israel Public Affairs Committee (Aipac) from 2002 to 2004.
Franklin also said he had met the political officer from the Israeli embassy at least nine times during the same period.
But he said he believed the Israeli government was already in possession of the information.
"He gave me far more information than I gave him," he said.
"It was never my intention to harm the United States, not even for a second."
He did not specify what US policy he was particularly frustrated with.
The two Aipac officials have pleaded not guilty to conspiring to communicate the information given to them by Franklin.