Spying on visiting foreign dignitaries is a longstanding habit not only of the British, but of many other countries as well. Most embassies in foreign capitals are designed with windowless safe rooms, on the assumption that their host country will be doing its best to monitor all their communications.

In 1985, the British government obtained injunctions attempting to gag the Guardian and Observer after they published disclosures by the renegade MI5 officer Peter Wright of wholesale British bugging. He and his colleagues had "bugged and burgled their way across London", during the cold war, he said.

He disclosed that MI5 bugged all diplomatic conferences at Lancaster House in London throughout the 1950s and 1960s, as well as the Zimbabwe independence negotiations in 1979....