The first two sentences of this article pretty well sum it up: “The main impact of US intervention in the Middle East has been to destabilize, polarize, and radicalize the region. Especially, it has fomented a vast, multi-country, new sectarian civil war between Sunni and Shiite Muslims.” From Dan Sanchez at antiwar.com:
The main impact of US intervention in the Middle East has been to destabilize, polarize, and radicalize the region. Especially, it has fomented a vast, multi-country, new sectarian civil war between Sunni and Shiite Muslims. On each side, the most sectarian forces have gained from the conflict. And benefiting the most have been fanatically intolerant and murderous Salafist groups like Al Qaeda and the Islamic State. Recent events show this pattern continuing apace.
In Iraq, the town of Ramadi, capital of Anbar Province, fell to the Islamic State in mid-May.
In Syria, the last government-held town in Idlib province fell to that country’s branch of Al Qaeda (Jabhat al-Nusra) on Friday.
In Libya, the town of Misurata, plus the bombed-out Gardabya air base, were abandoned to the Islamic State after a deadly suicide bombing, as it was revealed on Sunday.
In Yemen, Al Qaeda in the Arabian Peninsula (AQAP) seized an airport and an oil refinery in April.
Even in Saudi Arabia, the Islamic State suicide bombed a Shiite mosque on Friday (the second such deadly attack in recent weeks).
It is important to remember how we got to this point.
The 2003 US invasion of Iraq and complete dismantling of the Iraqi government completely destabilized the country, leading to a civil war between the Sunnis and Shiites. The US entirely took the Shiite side, and in particular backed the most sectarian and pro-Iran Shiite factions, which were then installed as the new government, following the ethnic cleansing of Sunnis in Baghdad.
The war raised the prestige and expanded the operations of Abu Musab al-Zarqawi’s organization, which later became Al Qaeda in Iraq (AQI), and ultimately the Islamic State. The Sunni tribes were only willing to ally with AQI because the brutal US forces and the virulently anti-Sunni Shiite brigades had proven to be an even worse threat. However, in 2006 the Sunni tribes turned on AQI, which then became marginalized.
However, the very next year the US, the Saudis, and their regional allies launched the “Redirection,” a strategic shift toward Sunni insurgents to counter the perceived “Shia Crescent” stretching from Iran to Syria that the US-installed Shiite government in Baghdad had filled in. This was largely at the behest of the Sunni Saudis and Israel, both of whom hate Iran.
http://original.antiwar.com/dan_sanchez/2015/06/01/salafists-gaining-ground/
To continue reading: Salafists Gaining Ground
