It’s a golden rule of politics: always assume the microphone is on.
But as many world leaders can testify, it’s a rule that’s often forgotten.
‘Hot mic’ moments have heaped embarrassment on politicians across the globe, from America to Australia.
Just this week, Canadian Prime Minister Justin Trudeau was caught appearing to mock US President Donald Trump at a Nato meeting.
Unguarded comments like these have been a source of humiliation, sometimes with huge political fallout.
They have also shone a light into the murky corridors of international diplomacy – for better or worse. Here are five of the most memorable.
1. Ronald Reagan: ‘We begin bombing in five minutes’ (1984)
At the height of the Cold War, US President Ronald Reagan turned up the diplomatic heat with a riff on Soviet Russia.
During a soundcheck before his weekly radio address, Mr Reagan joked with sound engineers who were recording him for NPR radio.
“My fellow Americans,” the president said. “I’m pleased to tell you…