Saudi Arabia and its close Gulf allies threatened to blockade Qatar. That's an act of war in international law, and I'm sure we can all agree that there's more than enough war in the region already. So this appears to be an instance where the US acted as a moderating influence against armed conflict. The US worked with Qatar to defuse the condemnation that the Saudis were heaping on it. It's all self-serving on the part of the US, of course. It would rather cede Texas to Mexico than have it's interests in the Persian Gulf go up in flames. Nevertheless, the threats from Saudi Arabia appear to be waning, and that can't be a bad thing.