Criminal investigation

The Rules of the Spy Game Are No Longer Clear

Some suspect the Kremlin is behind the attempted poisoning of an ex-spy. If so, it's a sign of a new and dangerous era.

...In 2010, the ex-colonel was one of four people who came to the West as part of a widely covered spy swap, in which the U.S. released 10 Russian "sleeper agents." There had been at least a dozen spy exchanges between Western countries and the Soviet Union and its satellites during the Cold War, but this was the first publicly announced one in the Vladimir Putin era.

None of the people traded to the West in these swaps has ever been assassinated. The possibility of a swap is a perk that makes it marginally worthwhile to spy for a foreign power. The money paid to spies or the moral satisfaction of working against a hated regime is never enough to compensate for the dreadful risk of this work; not even the implicit promise that the side you work for will take care of you will tip the scale if you have to look over your shoulder for the rest of your life. A swap, however, has been a guarantee of peaceful retirement. If that's no longer the case, this raises the stakes for spies -- and makes swaps pointless.

Having resumed the Cold War-era practice of swaps, why would Putin or his spy chiefs want to ruin it by approving the assassination of a former spy who had served part of his sentence in a Russian jail and was then put out to pasture in the U.K.?