India, June 7 -- The falling out between US president Donald Trump and Elon Musk, who bankrolled Trump's successful presidential bid last year and assumed an extraordinary role in his administration, echoes the souring of Trump's relationship with John Bolton during his first presidency. Musk endorsed a call for Trump to be impeached on X.com; Bolton, who left the first Trump presidency midway as the national security adviser, wrote a memoir explaining why Trump was unfit to occupy the Oval Office. Bolton's The Room Where It Happened (2020) paints a picture of a president allegedly at odds with many founding principles of the US - all too willing to make concessions to foreign authoritarians in exchange for electoral gains at home and not diffident about jeopardising historical alliances and American geopolitical positions. With insights on Trump's considerations and impulses, it could help understand Musk's turn from Trump champion to Trump critic....