Britain’s diplomatic feud with Russia escalated on Wednesday after the British government announced it would expel a senior Russian diplomat who officials claim is an “undeclared” military intelligence officer, and also shut down several Russian diplomatic facilities in the country. The government accused Russia’s foreign intelligence service, the Federal Security Service, or F.S.B., of a pattern of “malign activity” in Britain and Europe, including hacking and leaking trade documents relating to the United States, and targeting of British lawmakers through malicious email campaigns. James Cleverly, the British home secretary, told Parliament that the government was announcing the retaliatory measures “to make clear to Russia that we will not tolerate such apparent escalations.” Britain’s action came two days after the Russian Foreign Ministry said it had summoned the British ambassador to Moscow to lodge a “strong protest” over remarks the British foreign secretary, David Cameron, had made about Ukraine’s using weapons supplied by Britain to strike Russian territory. The British Foreign Office disputed that the envoy, Nigel Casey, had been summoned, characterizing it instead as a …