The short answer is, he did not. He was caught in an undercover sting operation in which an FBI agent posed as an Israeli spy. US officials have emphasized that the espionage charges filed Monday against Mr. Nozette do not implicate Israel itself.
The longer answer has yet to come, though, and is likely more complicated. Nozette clearly thought he was spying for Israel, according to a criminal complaint filed in US District Court. And US investigators first began tracking Nozette after they picked up indications he might be working for a foreign government.
"People who spy are motivated by ideology or money. You've got to run it to ground in either case to try and find out what was going on," says William Martel, an associate professor of security studies at The Fletcher School at Tufts University.
Why would Nozette even think Israel wanted an American spy? Historically, nations spy on each other if they feel they have a reason to do so, whether they are friendly with each other or not. That goes for the US as well as its allies.
"Countries are looking out for their interests," says Professor Martel, speaking generally and not specifically about the Nozette case.
But Israeli officials say their country ended any espionage against the US following the conviction of Jonathan Pollard, a former analyst for US Naval Intelligence, who was sentenced to life in prison in 1987 for spying for Israel.
Who is Stewart Nozette?
Among his more sensitive jobs was a stint as a physicist in the "O Division" of the Advanced Concepts Group at the Energy Department's Lawrence Livermore National Laboratory. He held a "Top Secret" security clearance from 1989 to 2006, according to the FBI.
"So any [sensitive work] that the US has done in space, I've seen," Nozette boasted to an undercover FBI agent during a lunch at the Mayflower hotel in September.
At that meeting, the FBI agent was pretending to be a representative of Mossad, Israel's espionage agency.
Appraised of this, Nozette reacted with aplomb, according to a transcript of the conversation excerpted in the court complaint.
"I don't get recruited by Mossad every day. I knew this day would come, by the way," said Nozette, according to the FBI.
"How's that?," asked the undercover agent.
"I just had a feeling, one of these days," said Nozette in reply.
So, why did Nozette have that "feeling"?
Nozette's Israel connections
According to the criminal complaint, between 1998 and 2008 Nozette worked as a technical consultant for an aerospace company that was wholly owned by the Israeli state.
During much of that time the company requested that Nozette provide it with technical data. Once a month, Nozette answered these questions. In return he received payments of approximately $225,000, according to the US government.
On January 6, 2009, Nozette flew out of Dulles Airport, outside of Washington, to an unnamed foreign country. Security officers searched his luggage and found two small computer "thumb drives" in his possession.
Upon his return three weeks later, US agents thoroughly searched his luggage. Those computer drives were nowhere to be found, according to the criminal complaint.
Near the end of his initial conversation with the FBI agent who was posing as his new Mossad handler, Nozette also said this:
"I thought I was working for you already. I mean, that's what I always thought, [the foreign company] was just a front."