Chaos is spreading throughout the Middle-East as nations divide along religious lines:
Catherine E. Shoichet and Mariano Castillo, "Saudi Arabia-Iran row spreads to other nations," CNN, January 4, 2016, http://www.cnn.com/2016/01/04/middleeast/saudi-arabia-iran-severing-ties-whats-next/
(CNN)The fallout of Saudi Arabia's execution of a Shiite cleric is spreading beyond a spat between the Saudis and Iranians, as other Middle East nations chose sides Monday and world powers Russia and China weighed in.ZeroHedge has a very good map of the distribution of Sunni and Shiite in the Middle East available here: http://www.zerohedge.com/news/2016-01-04/just-became-most-important-map-geopolitics
Bahrain announced Monday that it was severing diplomatic ties with Iran, citing Tehran's "blatant and dangerous interference" in Bahrain and other Arab countries. The United Arab Emirates said it was "downgrading" its diplomatic relations with Iran. The UAE recalled its ambassador in Tehran and said it would also reduce the number of diplomats stationed in Iran, according to state news agency WAM.
Earlier in 2015, Al Jazeera ran an interesting article about the tension between the Saudis and Shia
Martin Reardon, "Saudi Arabia, Iran and the 'Great Game' in Yemen," Al Jazeera, March 26, 2015, http://www.aljazeera.com/indepth/opinion/2014/09/saudi-arabia-iran-great-game-ye-201492984846324440.html
Reminiscent of the "Great Game" played out in Afghanistan between Great Britain and Russia more than a hundred years ago, Saudi Arabia and Iran are engaged in their own decades-long strategic rivalry for power and influence in the Middle East, stretching from the Mediterranean Sea to the Gulf and Arabian Sea. It is built mostly along sectarian and ideological lines - Saudi Arabia as the leader of the Sunni Muslim world, and Iran as the leader of the Shia Muslim world.Saudi Arabia is well armed in this conflict. It has been purchasing weapons from the US, paying cash, for decades. See this link for an interesting historical discussion: http://fas.org/asmp/profiles/saudi_arabia.htm.
While recent high-level discussions between the Saudi and Iranian foreign ministers would suggest a possible thawing in their cold relations, the fact of the matter is, too much bad blood exists between them for any meaningful, long-term rapprochement, at least in the near-term. The more likely state of affairs is that they are simply reassessing their strategies, taking into account all the events in the region, and preparing their next moves on the Middle East chessboard.
In fact, the Washington Post reported in 2015 that US weapons would play a significant role in Saudi Arabia's war in Yemen: https://www.washingtonpost.com/news/checkpoint/wp/2015/03/26/how-u-s-weapons-will-play-a-large-role-in-saudi-arabias-war-in-yemen/
In April 2015, Democracy Now asked whether Obama's record arms sales to the Saudis were playing a role in rising discord in the Middle East: http://www.democracynow.org/2015/4/7/are_obamas_record_arms_sales_to
It looks like they may have.
Epochal times we live in.