The United States has long considered Israel its closest ally in the Middle East. But the relationship, which hasn't always been an easy one, may have hit a new rough patch.

The FBI today arrested an 84-year-old New Jersey man and charged him with passing U.S. military secrets to Israel in the 1980s. According to a Department of Justice announcement, Ben-Ami Kadish delivered classified documents on U.S. nuclear weapons, combat aircraft and missiles to the same Israeli official who handled Jonathan Jay Pollard, the former civilian U.S. Navy intelligence analyst sentenced to life in prison after pleading guilty to spying for Israel in 1985.

Kadish, a former mechanical engineer at an army research center at Picatinny Arsenal, in Dover, N.J., would remove documents from a library at the facility and bring them to his home, where the Israeli official would photograph them, according to the charges filed in federal court in New York City.

Kadish, appearing frail and remaining silent, was released on $300,000 bail after his initial court appearance, according to Reuters, which quoted an Israeli Foreign Ministry spokesman as denying knowing anything about his arrest.

The Israeli official was not identified — he is referred to in the charges as CC-1 — but is said to have worked as the "consul for science affairs" at the Israeli consulate in Manhattan from at least 1980 through 1985.

According to the charges, CC-1 left the United States in November 1985, the same month that Pollard was charged with passing classified U.S. intelligence to CC-1.

Kadish's alleged spying took place between 1979 and 1985, although the charges say that he maintained contact with the Israeli official through last month, when CC-1 is said to have urged Kadish in a telephone conversation to lie to federal investigators.

"The following day, during an interview with the FBI, Kadish denied having had the telephone conversation with CC-1," the Department of Justice said.

Israel has acknowledged that Pollard spied for it, made him a citizen and has pressed the United States for his release, an issue that remains an irritant in U.S.-Israeli relations.

Just how the Kadish case will impact those relations remains to be seen. But wouldn't it be interesting to be a fly on the wall in those discussions?

"I know that we will be informing the Israelis of this action," said State Department spokesman Tom Casey. "I would simply say just as a general matter that 20-plus years ago during the Pollard case, we noted that this was not the kind of behavior we would expect from friends and allies, and that would remain the case today."