Marco Rubio has unique power to promote peace, but he hasn’t. He is almost as bad for the world as Trump | Simon Tisdall

As chief US diplomat, Rubio could do great good. His pandering and neglect are a disgrace we shouldn't ignore

Viewed from the state department in Washington DC, the world is on fire - but record heatwaves are not to blame. The unresolved Iran war has badly burned Donald Trump. His military campaign conclusively failed, energy and food prices are still rising, and a Republican rout in November's midterm elections looms. Humiliatingly, Israel this week flatly rejected his latest Gaza peace proposals, days after Trump congratulated himself on a historic breakthrough". In Europe, Russia's attacks on Nato allies grow increasingly brazen, threatening a wider escalation. The Ukraine war, which Trump vowed to end, is now well into its fifth year, with civilians on both sides caught in the killing fields. And these are just the bigger firestorms. There are plenty more.

Rarely has the need for effective, professional diplomacy been more pressing. So step forward Marco Rubio, US secretary of state and chief American diplomat. These are challenges that, if successfully tackled, could propel the 55-year-old son of Cuban immigrants and the former US senator for Florida into pole position in the 2028 Republican presidential nomination race. Here is a chance for Rubio to defy critics who dismiss him as a lickspittle and Trump dogsbody, and transform himself into respected global statesman. His boss mocked him as little Marco" and a loser" when they were election rivals in 2016. (Rubio called him a conman.) Now is Rubio's opportunity to go big, be brave and prove he's a winner.