For all Rishi Sunak's desire to be a big world player, Brexit has ensured a walk-on part

For a leader who is under siege at home, travel abroad can offer an alluring escape from domestic woes. When Rishi Sunak flies east this week to attend the G20 summit in New Delhi, he will be glad to put more than 4,000 miles between himself and the cost of living crunch, public services that are falling over and grisly opinion poll ratings. His international peer group will treat him with more courtesy than do many of his own MPs. Performing on what is loosely called "the world stage" will be a salve to the prime minister's self-esteem. What else…