Perhaps you are using a meaning of indiscriminate I'm unfamiliar with, but that statement is simply untrue. It would also be untrue for the United States.
Indiscriminate means "not marked by careful distinction". In the case of war, it means not always carefully distinguishing who will be killed by an attack.
Both Israel and the US, along with pretty much every other nation at war, have indiscriminately killed people. Dropping a bomb on populated buildings in a city is indiscriminate unless one can somehow know that every person within the buildings is a combatant.
The alternative of being indiscriminate when executing an attack in which we are fairly sure there will be collateral damage would be to intentionally target civilians (a tactic associated with terrorism).
Indiscriminate is already bad enough. Intentionally (discriminatorily) killing civilians would be far worse. I'd like to think neither Israel nor the US would intentionally do that.