Jeddah, Saudi Arabia (CNN) King Salman of Saudi Arabia has pulled off in Mecca what many had thought unlikely -- getting 20 or so disparate Arab nations to unite in a common position against Iran.

And while this achievement came without bellicose threats or new red lines, it is an important milepost on a road that may yet lead to regional conflict.

In middle-of-night, back-to-back summits at Islam's holiest of sites, the aging but still-attentive Saudi monarch got a double endorsement of his claims that Iran is destabilizing the Middle East and a backing of his call for "the international community to shoulder its responsibility.

The six-nation Gulf Cooperation Council and 21 Arab League nations present called for Iran to stop "interfering in the internal affairs" of its neighbors and denounced Tehran's "threat to maritime security" in the Persian Gulf.

For its part, Iran hit back, criticizing the allegations as "baseless" and accusing Saudi Arabia of promoting an "American and Zionist" agenda. Still, Tehran appeared tone-deaf to not one, but two unifying summit communiques urging it to change its behavior.

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