James ‘Mad Dog’ Mattis becoming trusted voice of reason in Trump administration

With President Trump still seemingly lurching from one controversy to another, a retired Marine general - ironically one with the nickname "Mad Dog" - is fast emerging as a moderating and stabilising voice in his administration.

Defence Secretary James Mattis is striking a very different tone to the president on key issues and is demonstrating a willingness to publicly voice those differences.

During his travels across the world this past week, he has:

• distanced himself from the president's fierce attacks on the nation's media

• said there was "very little doubt" Russia had meddled in democratic elections

• assured Iraqi leaders that America would not seize the country’s oil, despite Mr Trump’s threat.

The fact that Mr Mattis has had to make such comments or even suggest that America's closest allies should not take everything the president says seriously is pretty remarkable.

But Mr Trump's readiness to listen, trust and defer to his defence secretary’s opinion - even when it contrasts from his own - is a strong source of comfort to Republicans and Democrats, who have universally expressed admiration and respect for the former military commander.

Observers say his influence inside the White House is growing and has the potential to grow even further, with Michael Flynn’s replacement as national security adviser still to be decided.

If the opening month of the Trump presidency is anything to go by, Mr Mattis' steadying influence could be invaluable in these most unconventional and unprecedented of times in Washington.