By Humeyra Pamuk SDE BOKER, Israel (Reuters) -Israeli and Arab partners convened for a rare summit in Israel on Sunday attended by U.S. Secretary of State Antony Blinken, who sought to reassure the U.S. allies over Washington’s diplomacy with Iran. The issue is likely to dominate the two-day gathering, which includes foreign ministers from three Arab states that normalised ties with Israel in 2020, even as peacemaking with the Palestinians remained stalled. Blinken’s visit comes as some U.S. allies in the region question President Joe Biden administration’s commitment and brace for fallout fro…