President Joe Biden’s balancing act with Israel became increasingly difficult this week with the country’s deadly attack on an aid convoy in the Gaza Strip and an airstrike on Iran’s embassy compound in Damascus.

Both episodes tested the limits of Biden’s strategy, which has seen the U.S. president support Israel’s war against Hamas while criticizing the way it’s being conducted. They also drew new scrutiny to the question of U.S. leverage — how much Biden has over Prime Minister Benjamin Netanyahu and whether he’s willing to exert it.

"It’s not so much that the U.S. is losing leverage over Israel as it is that Washington has rightly been reluctant to use its leverage because it’s on big-ticket items” such as supplying advanced weapons and defending Israel at the United Nations, said Jonathan Panikoff, director of the Atlantic Council’s Scowcroft Middle East Security Initiative.