What is behind the delay in Iran’s promised retaliation against Israel?

"'A war with Israel would drag the US into a bigger conflict, which may hurt the chances of Kamala Harris in the November election. The Islamic Republic will do anything to stop Trump from being elected again,' Saeid Golkar, an associate professor of Political Science at the University of Tennessee at Chattanooga and senior advisor at United Against Nuclear Iran, told Al Arabiya English."