When David Ben-Gurion, one of Israel’s founding fathers, was warned in 1955 that his plan to seize the Gaza Strip from Egypt would provoke a backlash in the United Nations, he famously derided the U.N., playing off its Hebrew acronym, as “Um-Shmum.”

The phrase came to symbolize Israel’s willingness to defy international organizations when it believes its core interests are at stake.

Nearly 70 years later, Israel faces another wave of condemnation in the United Nations, the International Court of Justice, and from dozens of countries over its military operation in Gaza, which has killed an estimated 29,000 Palestinians, many of them women and children, and left much of the territory in ruins.

The huge swell in global pressure has left the Israeli government and its prime minister, Benjamin Netanyahu, deeply isolated, if not yet bowed, largely because it still has the support of its staunchest ally, the United States.

This time, though, Israel faces a rare break with Washington. The Biden administration is circulating a draft resolution in the United Nations Security Council that would warn the Israeli military not to carry out a ground offensive in Rafah, near Egypt, where more than a million Palestinian refugees are sheltering. It would also call for a temporary cease-fire as soon as practical.

“It’s a big problem for the Israeli government because it has previously been able to hide behind the protection of the United States,” said Martin S. Indyk, a former American ambassador to Israel. “But now Biden is signaling that Netanyahu can no longer take that protection for granted.”