US President Joe Biden warned Israeli Prime Minister Benjamin Netanyahu on Thursday that American policy on Israel depends on the protection of civilians in Gaza, in his strongest hint yet of possible conditions on military aid after an Israeli strike killed seven aid workers. In their first call since the killing of the employees of the US-based World Central Kitchen (WCK) group on Monday, Biden also called for an “immediate ceasefire” after the “unacceptable” attack and wider humanitarian situation in Gaza. Biden, a Democrat, is facing growing pressure in an election year over his support fo…