The United States has taken a public distance from Israel as never before over the Gaza war but the decisive test will be Rafah and whether Israel heeds U.S. warnings against an offensive in the packed city.

The United States on Monday abstained at the Security Council, allowing a resolution to pass for the first time that called for an immediate ceasefire, infuriating Prime Minister Benjamin Netanyahu who delayed a delegation to Washington to discuss U.S. concerns on Rafah.

But in a stance surely noted by Netanyahu, President Joe Biden has made clear he will not use his key point of leverage cutting U.S. military assistance to Israel.

Annelle Sheline, who recently resigned in protest from the State Department, where she had been on a fellowship working on human rights, said the Biden administration may be shifting but that its actions so far — including the resolution and plans for an emergency pier to bring in aid — amounted to "PR stunts."

I can only hope that things are starting to change. Unfortunately, I don't yet see the US actually using its leverage as far as ending or withdrawing support for Israeli military operations, turning off the tap of weapons," she told AFP.

Michael Singh, managing director of the Washington Institute who was a top White House aide on the Middle East under former president George W. Bush, said Biden was responding at the United Nations not just to domestic politics but to calls from U.S. allies to compromise and not keep vetoing resolutions.

A resolution "is a signal, but it doesn't in any tangible way impact Israel's ability to prosecute the conflict," Singh said, while arms restrictions would "come at a much higher cost" strategically and politically. (AFP)