John Bolton out as US national security adviser - BBC News
He is the third of President Trump's national security advisers to leave their role.
Mr Bolton and Mr Trump did not always see eye-to-eye. Indeed, when announcing Mr Bolton’s departure, Mr Trump said he “disagreed strongly with many of his suggestions”.

Mr Bolton did have a hand in some of Mr Trump’s major security decisions.

Most notable was Mr Trump’s decision to withdraw the US from the 2015 Iran nuclear deal. But while Mr Trump favoured a new deal with Iran, Mr Bolton wanted to overthrow its regime altogether.

Regime change in Venezuela and North Korea was on Mr Bolton’s agenda, too.

In Venezuela, Mr Bolton helped orchestrate a campaign to remove President Nicolás Maduro from power. In North Korea, Mr Bolton lobbied Mr Trump to end Kim Jong-un's reign with a pre-emptive strike.

Neither happened on his watch, and Mr Trump went his own way on North Korea, hosting media-friendly summits instead of raining down missiles.

Pacts and deals, it seems, are not words in Mr Bolton’s vocabulary. He also pushed for Mr Trump to pull out a key nuclear treaty with Russia this year.

Towards the latter stages of Mr Bolton’s time in office, it was the war in Afghanistan that widened his rift with Mr Trump.

To Mr Bolton's dismay, Mr Trump announced the withdrawal of thousands of US troops from Afghanistan. To make matters worse, Mr Bolton was sidelined from talks with the Taliban to end the 18-year conflict.