Mr Kadish was an engineer at the US army's Armament Research Centre
A military engineer has appeared in court in the US on charges of passing classified information to Israel.
Ben-Ami Kadish is alleged to have given secrets involving information about nuclear weapons, fighter jets and missiles to Israel in the 1980s.
He was charged with four counts of conspiracy, including disclosing documents relating to national defence and acting as an agent of Israel.
He declined to comment on leaving the Manhattan courthouse.
"I'm not saying anything. I have no comment," said Mr Kadish, 84, who worked at the US army's Armament Research, Development and Engineering Centre in New Jersey from 1979 to 1985.
He was released on bail of $300,000 and restrictions were placed on his travel.
US state department spokesman Tom Casey discusses the charges
Mr Kadish is accused of giving the material to an Israeli consular official.
His alleged handler has been named by justice officials as the former consul for science affairs at the Israeli Consulate General in Manhattan, reportedly the same person who dealt with Jonathan Jay Pollard, who is serving life in prison for spying for Israel.
Pollard passed thousands of documents to Israeli agents while working at the US defence department. He was convicted in 1987.
The Israeli government publicly admitted in 1998 that Pollard had been their agent and awarded him Israeli citizenship.
'Major weapons system'
According to the complaint filed in Manhattan federal court, Mr Kadish borrowed several classified documents related to national defence from the army's research centre between 1980 and 1985 and took them to his home in New Jersey.
Mr Kadish would then hand over the documents at his home to the Israeli consular official, who would photograph them in the basement, it added.
Among others, Kadish took documents linked to modified designs for F-15 jets
The complaint said Mr Kadish appeared to have received small gifts and restaurant meals for his alleged spying - not cash.
One of the documents "contained information concerning nuclear weaponry and was classified as 'Restricted Data'... because the document contained atomic-related information", the complaint said.
Another, classified as "Secret" and "Not Releasable to Foreign Nationals", contained "information concerning a major weapons system - a modified version of an F-15 fighter jet that the United States had sold to another country".
Modified F-15s have been sold to Israel, Japan, Saudi Arabia, Singapore and South Korea.
Documents relating to the US Patriot missile air defence, classified as "Secret", were also borrowed by Mr Kadish from the library.
'Don't say anything'
The court documents also allege that Mr Kadish lied to US law enforcement officials on 21 March 2008, the day after he was told to do so by his Israeli handler during a telephone conversation.
In that conversation, Mr Kadish's handler was quoted in the complaint as telling him: "Don't say anything... What happened 25 years ago? You don't remember anything."
The United States is a close ally of Israel and supplies more than $2 billion a year in military aid. The two countries also co-operate in developing some areas of military technology.
State Department spokesman Tom Casey said Israel would be informed of the case against Mr Kadish.
"Twenty-plus years ago, during the Pollard case, we noted that this was not the kind of behaviour we would expect from friends and allies, and that would remain the case today," he said.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.