As fighting in Gaza resumed, U.S. Secretary of State Antony Blinken issued strong words of caution for Israel to obey international humanitarian law and to minimize civilian casualties. It was a significant shift in tone compared to the total support Blinken had delivered earlier in the war. And it's a message that's been echoed by U.S. Vice President Kamala Harris and Defense Secretary Lloyd Austin.

Are the long-time allies at odds over Gaza? What does strain in that relationship mean for the future of the war – and for the civilians caught in the middle?

Gregg Carlstrom, Middle East Correspondent for The Economist, explains.