Russian President Vladimir Putin is an increasingly lonely and vulnerable leader, and stamping out dissent following his invasion of Ukraine could be his undoing, Australia’s foreign spy chief said in a rare interview.

Warning that the clash between democracies and authoritarian states was getting “starker”, Australian Secret Intelligence Service director-general Paul Symon said the sharing of intelligence among Western agencies in the run-up to the war and since fighting broke out in Ukraine was at an unprecedented level.