And, who wins? The Guys Who Control the Game: MCAM — Military Contractors & Arms Manufacturers
Iran has NEVER been our enemy — but we have been the enemy of Iran since we overthrew their democratically-elected prime minister, Mosaddegh, in 1953. The 1979 Iranian Student Revolution resulted in the overthrow of the brutal dictator, Shah Mohammed Rezi Pahlavi, which America brought to power in 1953 and supported for some 25 years. The Shah murdered tens of thousands and terrorized the Iranian population. He was one of the most heinous men in history. The take-over of the US Embassy in Tehran occurred when Carter allowed the Shah to seek political asylum for medical treatment in the US.
The USA furthered the development of Saudi Arabia (arming and funding the Saud tribe) to secure oil in the Middle East (ARAMCO), not to build friendship or bring justice to the region. Reagan (i.e., Charlie Wilson's War) funded and furthered Salafi/Wahabbi extremism in Saudi Arabia and Pakistan to covertly confront the USSR in Afghanistan during the 1980s.
The Saudi government did not fund nor did they support the 9/11 attacks. Usama bin Laden (one of 50+ children from the rich, powerful Bin Laden family and major player in Saudi Arabia) had been kicked out of the country for his extremist and anti-regime views. He took his money, resources and base, al Qaida in Arabic, to Afghanistan where he masterminded the 9/11 attacks.
ISIS was born largely as the result of our murder of moderate, but Sunni Saddam, and disbanding of his Sunni supporters and army. Bush & Cheney threw tens of thousands of military and powerful men into the streets with their weapons without options for jobs, income or means to support their families.
According to a report by the German publication, Der Spiegel, a former intelligence officer, a colonel, for the late Iraqi dictator Saddam Hussein's air defense force, Samir Abd Muhammad al-Khlifawi, who went by the pseudonym Haji Bakr, was the mastermind behind Islamic State's takeover of northern Syria. Bakr is described as being "bitter and unemployed" after U.S. authorities in Iraq disbanded the army by decree in 2003. Between 2006 to 2008 he was reportedly in U.S. detention facilities, including Abu Ghraib prison. They have united with disenfranchised Sunnis in Syria, who have opposed the Shia-dominated Asad regime for decades. Joh Soltz, co-founder of VoteVets.org and Iraq war veteran, points out:
The space that ISIS has been given to operate largely is a byproduct of the Iraqi government continually driving Sunnis out of any position of influence. For example, I still talk with members of the Iraqi Army whom I trained as part of my second tour in Iraq. Almost immediately they reported to me that Nouri al-Maliki's government started firing Sunni officers and replacing them with untrained or undertrained Shia. When a group like ISIS comes along and starts fighting such a government, all too often Sunnis will give them the space to operate -- if not join them.And, we were warned. Sandra Mackey, who recently died, wrote in a 2002 book "The Reckoning -- Iraq and the Legacy of Saddam Hussein," and predicted some of the outcomes of the war in Iraq.
Moreover, many of the ISIS fighters are made up of the very same Sunni insurgents we fought in Iraq — former members of al-Qaeda in Iraq, the Nusra Front, and more. Many of them packed their bags, moved up into Syria, joined with other splintered radicals, and became ISIS.
So if you want to peg just one good reason that ISIS exists, it is because of our invasion of Iraq. Had we not invaded Iraq, there would have been no strong insurgency that eventually morphed into ISIS. 
"If war prevails, we shall beget a greater disorder in the Persian Gulf," Mackey wrote. "We will be sucked into the resentments of the Arab world, the hostilities of the Iraqis, and the challenge of nation building in what has become an intensely tribal society at the core of American vital interests in the oil-rich Persian Gulf."Liz Sly is the Washington Post's Beirut bureau chief. She has spent more than 15 years covering the Middle East, including the Iraq war. Other postings include Africa, China and Afghanistan. She reports:
She said those calling for an invasion of Iraq "cannot ignore the threats to American security that could come with Hussein's demise. With American troops on the ground and no governing authority capable of taking charge, the United States faces the real possibility of a secular version of militant Islam." (we now face ISIS)
"Thus, American military forces rotate in and out, U.S. taxpayer money finances the occupation, and Iraqi hostility to a Western presence increases. There is no exit strategy except retreat." 
Abu Hamza, who became the group's ruler in a small community in Syria, never discovered the Iraqis' real identities, which were cloaked by code names or simply not revealed. All of the men, however, were former Iraqi officers who had served under Saddam Hussein, including the masked man, who had once worked for an Iraqi intelligence agency and now belonged to the Islamic State's own shadowy security service, he said.The Shia-dominated government that resulted in Iraq has hunted down many Sunnis in retaliation for the terror the Saddam regime inflicted on their population over decades.
Even with the influx of thousands of foreign fighters, almost all of the leaders of the Islamic State are former Iraqi officers, including the members of its shadowy military and security committees, and the majority of its emirs and princes, according to Iraqis, Syrians and analysts who study the group.
In Syria, local "emirs" are typically shadowed by a deputy who is Iraqi and makes the real decisions, said Abu Hamza, who fled to Turkey last summer after growing disillusioned with the group. He uses a pseudonym because he fears for his safety.
"All the decision makers are Iraqi, and most of them are former Iraqi officers. The Iraqi officers are in command, and they make the tactics and the battle plans," he said. "But the Iraqis themselves don't fight. They put the foreign fighters on the front lines."
The raw cruelty of Hussein's Baathist regime, the disbandment of the Iraqi army after the U.S.-led invasion in 2003, the subsequent insurgency and the marginalization of Sunni Iraqis by the Shiite-dominated government all are intertwined with the Islamic State's ascent, said Hassan Hassan, a Dubai-based analyst and co-author of the book "ISIS: Inside the Army of Terror."
"A lot of people think of the Islamic State as a terrorist group, and it's not useful," Hassan said. "It is a terrorist group, but it is more than that. It is a homegrown Iraqi insurgency, and it is organic to Iraq." 
Iraq was always destined to fall back into chaos because President Bush backed a prime minister, Nouri al-Maliki, who is a Shiite who exacted political revenge on the Sunni minority in Iraq by driving them out of positions of power, including in the military. The underlying issues in Iraq were political, are political, and always will be political. As long as the minority feels like it has to fight against the Shia government for rights and stability, Iraq will be a mess. This more than anything has allowed groups like ISIS the space they need to operate in majority-Sunni regions. Predominately Sunni Saudi Arabia and predominately Shiite Iran have historical tensions due to the split in Islam stemming the the death of Mohammad. The Arabian peninsula's poorest country, Yemen, is now divided between a Saudi-backed exiled government and Iran-backed Shi'ite fighters who control the capital.
Yemen's embattled president on Saturday called Shiite rebels who forced him to flee the country "stooges of Iran," directly blaming the Islamic Republic for the chaos there and demanding airstrikes against rebel positions continue until they surrender. Israel is the wild card, as the western Christian-dominated world led by the US and Britain voted in 1948 to create a Jewish state in the middle of Arab/Muslim dominated Palestine over the objection of ALL Muslims, Sunni and Shiite.