An ex-US campaign advisor who has sat with the world's dictators explains Donald Trump's increasingly authoritarian tactics and the threat they pose to American democracy.

Donald Trump isn't a despot. But he is increasingly acting like the "despot's apprentice", an understudy in authoritarian tactics that threaten to erode American democracy, including attacking the press, threatening rule of law by firing those who investigate his alleged wrongdoings, using nepotism to staff the White House, and countless other techniques.

Donald Trump is borrowing tactics from the world's dictators and despots. Trump's fascination with the military, his obsession with his own cult of personality, and his deliberate campaign to blur the line between fact and falsehood are nothing new to the world of despots. But they are new to the United States. With each authoritarian tactic or tweet, Trump poses a unique threat to democratic government in the world's most powerful democracy.

At the same time, Trump's apprenticeship has serious consequences beyond the United States. His bizarre adoration and idolization of despotic strongmen - from Russia's Putin, to Turkey's Erdogan, or to the Philippines' Duterte - has transformed American foreign policy into a powerful cheerleader for some of the world's worst regimes.

The Despot's Apprentice: Donald Trump's Attack on Democracy explores how Trump uniquely threatens democracy - and how to save it from him.