"Some have speculated that the obvious nature of a polonium poisoning pointed away from Putin. Such a blatant use of a closely controlled substance would immediately implicate the Russian government, the argument goes, and therefore would never have been used by real FSB agents. However, the British say that the assassination was meant to send a clear message to Putin's critics and anyone tempted to offer information to Western nations about the activities of the Putin regime.

The Russians are not happy about the direction of the investigation. They're threatening the UK by suggesting that the probe has damaged diplomatic relations. The British ought to point out that conducting assassinations in their country damages diplomatic relations as well."