As President Vladimir V. Putin of Russia has pursued enemies abroad, his intelligence operatives now appear prepared to cross a line that they previously avoided: trying to kill a valuable informant for the U.S. government on American soil.
The clandestine operation, seeking to eliminate a C.I.A. informant in Miami who had been a high-ranking Russian intelligence official more than a decade earlier, represented a brazen expansion of Mr. Putin’s campaign of targeted assassinations. It also signaled a dangerous low point even between intelligence services that have long had a strained history.
“The red lines are long gone for Putin,” said Marc Polymeropoulos, a former C.I.A. officer who oversaw operations in Europe and Russia. “He wants all these guys dead.”
[Editor’s Note: Surprised this has not been happening more. On 4 March 2018, Sergei Skripal, a former Russian military officer and double agent for the British intelligence agencies, and his daughter, Yulia Skripal, were poisoned in the city of Salisbury, England. According to UKGOV sources and the Organization for the Prohibition of Chemical Weapons (OPCW), they were poisoned by means of a Novichok nerve agent.]