DUBAI, United Arab Emirates — Bracing itself for a retaliatory strike from Israel, Iran has been urging its Arab neighbors not to allow Israel to use their airspace, two diplomats from Gulf nations told NBC News on Friday. 

Israel has vowed to respond to last week’s ballistic missile attack by Iran, prompting Tehran to warn countries that helping Israel in any way could potentially escalate into war, one of the diplomats said. Both asked not to be named because they were not authorized…