SCOTT SHANE

WASHINGTON - Ideology and money used to be the primary motives for spies, but now there is a historic shift in the nature of spying against the United States. Divided loyalty, usually on the part of naturalized Americans with roots in a foreign land, has become a driving force.
From 1947 to 1990, a United States Defense Department study found, fewer than 1 in 5 Americans charged with spying were acting solely or primarily out of patriotic, as opposed to ideological, loyalty to a foreign country. Since 1990, according to the study’s author, Katherine L. Herbig, divided loyalty has been the sole or primary motive in about half of all cases.
“Dual loyalty is a problem we haven’t seen on such a scale since the Revolution, when many colonists swore allegiance to the British king, said Joel F. Brenner, the top counterintelligence official in the office of the director of national intelligence in the United States.
Chi Mak’s case represents the new shift in spying. One day in February 2005, F.B.I. agents fished a pile of paper scraps from the trash of Mr. Mak, an engineer for a California defense contractor. Painstakingly reconstructed, the torn-up notes turned out to be what the bureau believed were instructions for Mr. Mak on what technical information to steal and deliver to China.
Mr. Mak, who emigrated from China three decades ago and became a United States citizen in 1985, was sentenced in March to 24 years in prison for illegally exporting controlled information and lying about it. Addressing the judge who said he had betrayed the United States, Mr. Mak, 67, protested: “I never intended to hurt this country. I love this country.
The trend has come to light at an awkward time for American intelligence agencies. Admitting that they can hardly hope to penetrate Al Qaeda without greater expertise in Arabic or fend off Chinese espionage without more fluent speakers of Chinese, the Central Intelligence Agency and National Security Agency are dropping old security policies that excluded many Americans with foreign relatives from high-level clearances.
But even as the American government aggressively courts first-generation and second-generation Americans, the new statistics suggest, it must keep a wary eye out for those whose real loyalty is to their native country or to militant Islam.
“The intelligence community has a particularly difficult risk to manage, Mr. Brenner said. “It’s difficult to do background checks on people from outof- the-way places. Why do people betray their country- Counterintelligence instructors have long offered the mnemonic MICE, for money, ideology, ompromise, ego. Perhaps it’s time to update that to MINCE, adding nationalism . Or MINCES, noting the contributions of sex, as in the case of Donald W. Keyser, a United States State Department official whose liaison with a Taiwanese intelligence officer led to a conviction last year for possession of classified documents and lying to investigators.
Rarely is only one motive at play for a spy. But different periods have featured different motives in the ascendancy.
The first great wave was ideology, growing from an early fascination with the Soviet experiment, which promised freedom from the grinding inequities of capitalism. Julius Rosenberg, for instance, whose parents worked in New York City sweatshops, was one of dozens of American and British Communists who fed secrets to Soviet intelligence in the first half of the 20th century.
But by the 1970s, disillusionment with the crimes of Communism meant that few took up the Soviet cause gratis. Money dominated the second wave .
The third wave of spying shows much less greed. Money, the sole or primary motive for two-thirds of spies who got their start in the 1980s, was the main draw for just a quarter of spies from 1990 to date, Ms. Herbig’s new analysis concludes. No money at all was paid in the 11 most recent cases.
The largest share was made up of naturalized Americans who spied out of devotion to another country: Cuba, the Philippines, South Korea, Egypt, Iraq. In a handful of cases, Muslims have been accused of ties to Al Qaeda or other terrorist groups; these include Hassan Abujihaad, an American convert to Islam convicted in March of supplying information on Navy ships to a suspected terrorist financier.
Then there is the rash of Chinese cases, notably that of Mr. Mak. And an indictment for economic espionage was unsealed in February in California against another American citizen of Chinese birth, Dongfan (Greg) Chung, a 72-year-old engineer for defense contractors. The indictment quotes a letter Mr. Chung was accused of sending to a technology institute in China in the late 1970s with an emotional offer of help.
“I would like to make an effort to contribute to the Four Modernizations of China, he wrote.
According to the federal indictment, the Chinese were eager for his help. “We are all moved by your patriotism, Professor Chen Lung Ku of the Harbin Institute of Technology wrote in September 1979. “We’d like to join our hands together with the overseas compatriots in the endeavor for the construction of our great socialist motherland.