With the Americans providing intelligence to Saudi forces as they bomb Houthi rebels in Yemen and unofficially allow Iran to back Iraq in its fight with Islamic State, it seems Obama is meddling in a part of the world that is already at boiling point.
The Americans are friends with the Saudis because of the oil they supply and the lucrative arms deals that the Saudi armed forces need to keep their war machine afloat. Saudi is a country with harsh Wahabi Sharia law in place, a place where immigrants and women are downtrodden, the Americans and the West in general knows this and turns a blind eye unless of course words are said in private. Saudi Arabia is a country whose human rights record is as bad as any other dictatorship in the world but it suits the US and the West to have friendly relations with it, possibly for the reasons outlined in this paragragph.
As mentioned with the nuclear talks in Switzerland with Iran, which may or may not reach a final agreement, the U.S. is involved in these talks and as stated earlier the U.S. is allowing Iranian air and ground forces to back Iraqi armed forces as they struggle with Islamic State forces in the battle for Tikrit. Then Obama and Rouhani have spoken by phone and Obama has even said that Iranian - U.S. relations could return to something akin to normality if a deal is reached over its nuclear programme.
Now given that Saudi and Iran are bitter enemies, it seems the U.S. could be playing a dangerous game here, because if the Iranians and the Saudis went to war, who would the U.S. side with or would it stay out of any conflict? One would have thought the U.S. may side with the Saudis but then the U.S. would look hypocritical on the world stage, siding with Saudi while the it had been trying to court a potential new friend, Iran.
The Saudi Arabians and the Iranians have always hated one another, ever since the Iranian revolution in 1979 and the subsequent Iran-Iraq war 1980-1988. Both are Islamic but their doctrines are so far apart in ideology, Iran is a Shia government that thinks only clerics should rule in an Islamic republic devoid of royalty and hates the Wahabism of the Suni government of Saudi Arabia. Saudi Arabia hates the Iranian regime and all it stands for, both face each other across the Persian Gulf.
Both Saudi and Iran wield influence across the Middle East and beyond; for example, the Saudis back the Yemeni government in exile whereas the Iranians back or are accused of backing the Houthi rebels in Yemen. So there is no love lost between either side, then factor into that the U.S. involvement with both sides and you cannot rule out Israel so the Middle East could be a literal volcano waiting to explode.