Trump was warned of likely Iranian retaliation on Gulf allies, sources say

President Donald Trump was warned that attacking Iran could trigger retaliation against U.S. Gulf allies despite his claims on Monday ​that Tehran's reaction came as a surprise, said a U.S. official and two sources familiar with U.S. intelligence reports.
Pre-war ‌intelligence assessments did not say that Iran's response was "a guarantee, but it certainly was on the list of potential outcomes," said one source, who like the other two requested anonymity to discuss the issue.