Are you claiming Harris or Biden would have bombed Iran like this? That does not sound credible, but if the other party wouldn’t have attached Iran then this is not business as usual, it’s the GOP as usual.
Biden and Harris didn't have any problems shipping tons of bombs to Israel, aimed at being exploded on dense civilian zones so I don't think that there is are dramatic differences between the two parties.
Trump doesn't need congressional approval to launch operations shorter than 60 days, per the War Powers act, a law introduced by Democrats, by the way.
This isn't a simple operation, killing a foreign head of state is about as clear of a declaration of war as you can imagine. The law was introduced to put a check on the president's use of military force, it didn't give the president the power to declare war on another country.
"Harris to Jewish voters: ‘All options on the table’ to stop Iran from going nuclear
In pre-election High Holidays call, US vice president says diplomatic solution still preferable to keep Islamic Republic from the bomb, charges Trump won’t stand by Israel"