HE’S a tough-as-nails military veteran who’s served in some of the world’s worst warzones. In his five-decade career John Kelly commanded so much respect that men were willing to put their lives on the line following his orders.

But some are warning that the trouble the highly decorated general faced on the battlefield is nothing compared with what he’s going to be dealing with now as American president Donald Trump’s new right-hand man. It’s not for nothing that the position of White House chief of staff is known as the worst job in Washington – Kelly’s predecessor, Reince Priebus, lasted just six months.

Trump has always been the kind of boss who likes to stir things up – pitting rivals against one another and encouraging factions, infighting and petty squabbles. And while it made for entertaining TV on his reality show The Apprentice, in America’s highest office it’s spelt disaster. Insiders say that under Trump (71) the White House is becoming more dysfunctional by the day.

With key members of his staff resigning in record numbers or rebelling to the point where he’s had no choice but to fire them, even he seems to have realised it’s time for a change.

“General Kelly has been a star and done an incredible job thus far – respected by everybody. He’s a great, great American,” the president wrote in a series of tweets announcing that Priebus was out and Kelly was in.

After two weeks of turmoil which saw the resignation of White House press secretary Sean Spicer and the sacking of Priebus and Anthony Scaramucci – the short-lived White House communications director – the news of Kelly’s appointment was greeted with enthusiasm even by Trump’s fiercest critics.