Prime Minister Theresa May of Britain declared an end to a mystery that was really no mystery. It was “highly likely,” Mrs. May said on Monday, that a former Russian spy and his daughter were poisoned in Salisbury, England, by Russian agents in an “indiscriminate and reckless” attack.
The attack on the former spy, Sergei Skripal, who worked for British intelligence, and his daughter Yulia, in which a police officer who responded was also poisoned, was no simple hit job. Like the 2006 murder of Alexander Litvinenko, another British informant, who was poisoned with radioactive polonium 210, the attack on Mr. Skripal was intended to be as horrific, frightening and public as possible. It clearly had the blessing of President Vladimir Putin, who had faced little pushback from Britain in the Litvinenko case.
The blame has been made clearer this time and this attack on a NATO ally needs a powerful response both from that organization and, perhaps more important, by the United States.
Mr. Putin has faced little backlash for actions even bolder than the gruesome intrigues in Britain, like the attacks by Russian forces in Ukraine and Syria. With growing support from autocratic forces in Europe, he must not be emboldened to think he will be unchecked. While President Trump has allowed Mr. Putin a free hand to meddle in American politics, he cannot ignore yet another attempted murder of a Putin foe on allied soil. The administration needs to enforce sanctions Congress has already passed and press NATO to do more, perhaps banning travel by Putin cronies and enacting other restrictions on business activities.
Not to silence him, presumably, because the Russians themselves had released him to Britain in 2010 in a swap for a network of sleeper agents rounded up in the United States. The likely answer was provided by Mr. Putin himself a few months after Mr. Skripal was traded to the West. Asked during his annual give-and-take with reporters in 2010 how he would treat treason, Mr. Putin, a former K.G.B. agent, replied: “Traitors will kick the bucket, trust me. These people betrayed their friends, their brothers in arms. Whatever they got in exchange for it, those 30 pieces of silver they were given, they will choke on them.”
Mrs. May demanded that Russia immediately provide complete disclosure of the Novichok gas program to the Organization on the Prohibition of Chemical Weapons. Then she said the government was drawing up a full range of retaliatory options.
These could range from expelling some Russian diplomats, as Britain did after Mr. Litvinenko’s poisoning in 2006, to stronger sanctions. The trouble is that Russia probably doesn’t much worry about diplomatic expulsions, and British sanctions would add little to the broad range of Western sanctions already in place over the annexation of Crimea.
Yet if Russia’s message is that no “traitor” is safe anywhere, it should be in the interest of every nation to send an indelible message to Mr. Putin that he cannot deploy his weapons of war anywhere he wants.