2013: ATTACK ON DIPLOMAT
The United States expelled two Russian diplomats in retaliation for a bizarre episode outside the US Embassy in Moscow in June 2013, in which a Russian police officer attacked a US diplomat.
Russian television said the American was an undercover Central Intelligence Agency (CIA) operative, while the State Department said he was an "accredited diplomat" who had been assaulted as part of systematic harassment of US Embassy staff by the Russian authorities.
2013: HAIR-RAISING EPISODE
In May 2013, the Russian government expelled a US Embassy official identified as Ryan C. Fogle. He was arrested after being caught carrying two wigs - one blond and one brown - a Moscow street atlas, US$130,000 in cash and a letter offering "up to US$1 million a year for long-term cooperation".
2010: SLEEPER CELL WOKEN UP
In 2010, 10 Russians accused of being members of a sleeper cell were deported after pleading guilty to conspiracy in a Manhattan court. As part of a deal, the spies were swopped for four Russian prisoners, three of whom were serving sentences on treason convictions.
2001: FBI TURNCOAT
In March 2001, the US expelled 50 Russian diplomats in the wake of the arrest of Robert Philip Hanssen, a counter-intelligence expert at the Federal Bureau of Investigation who had spied for Moscow for more than 15 years.
US officials said he had been paid hundreds of thousands of dollars after he volunteered to turn over US secrets to Russia.
In response, Russian officials kicked out several US diplomats.
1994: MILD BLOWBACK
In February 1994, shortly after the arrest of Aldrich Ames, a career CIA officer who turned out to be a double agent, the US expelled senior Russian diplomat Aleksandr Lyskenko, whom it called a top intelligence service officer.
The US response was considerably less severe than it would have been as the Clinton administration supported the new government of President Boris Yeltsin after the fall of the Soviet Union.
1986: MASS EXPULSION
President Ronald Reagan expelled 55 Soviet diplomats in November 1986 in an effort to curb spying. Moscow then ordered 260 Soviet employees of the US Embassy to stop working.
The conflict arose after a Soviet employee of the United Nations, Gennadi Zakharov, was arrested for spying. The Russians responded by arresting Nicholas Daniloff, the Moscow correspondent for US News & World Report, and accusing him of spying. He was released two weeks later.