JPMorgan Chase has “run scenarios that will shock you” in preparation for potential global conflict, Dimon told the audience.

He's known as a Jamie Dimon protegé, a 9/11 hero, and an operational expert. Now Fiserv's Frank Bisignano can add government hell-raiser to his résumé.

The move comes as increasing number of firms wrestle with how best to coax staff back into the office more regularly.

The British-headquartered lender unveiled a more stringent approach to hybrid working in a memo to staff earlier this week, which cut the minimum number of days staff can work from home from three ...