Investors and their advisers are having to deal with a new style of geopolitics being driven by the world’s superpowers, according to a former head of MI6.

Sir John Sawers, Chief of the UK’s Secret Intelligence Service from 2009 to 2014, told the Guernsey Finance Private Wealth Forum in London that the presidency of Donald Trump was signalling change not only in the United States but also around the world. 

“The state of the world was once fairly predictable,” he said. “Now there are interesting changes in the outlook for international investment in a very rapidly changing world. The last few years have s...