Jihad has been ongoing for 1,500 years. Trying to blame the U.S. is ridiculous.
Rubbish.
The Ottoman Empire quashed it for over 500 years. After its demise in 1918, and after Great Britain and France divvied up the spoils (Sykes Picot), despots installed by Western powers (Great Britain, France, US) to rule over their 'interests' kept a lid on it. Then the secularism of Egypt's Gamal Abdel Nasser made it irrelevant. Then came the oppression and poverty, plus (our close and trusted ally) Saudi Arabia's spreading of its own fundamentalist Wahhabism throughout the world, brainwashing young impressionable kids into becoming violent Jihadists.
The US plotted to overthrow the elected Iraninan PM Mossadegh in 1954 because he wanted to nationalize British petroleum interests . Ironically, the British were replaced by US oil companies. They replaced Mossadeh with the Shah, and helped him maintain an oppressive police state with the US trained Savak secret police. That pressure cooker blew up with the Iranian revolution that was then highjacked by the clerics. Then the Iran Iraq war with Saddam (installed by the CIA) goaded by the US into attacking Iran (enemy of the US).
Then Saddam turning against Kuwait because the latter were slant drilling for oil inside Iraq, plus the Emir of Kuwait told Saddam to go fuck himself when the latter asked for long promised compensation for protecting Arabia against the Persians. That set the seed for the current turmoil.
Saddam was then villified thanks to a brilliant PR campaign in the US, financed by the deposed Ruler of Kuwait (babies dumped out of incubators, witnessed by the daughter of the Kuwaiti embassador who happened to be in the US at the time). The US then set its sights on Iraq and destabilised its multi ethnic and multi confessional status under the false pretext that they had WMD and were involved in 911. Not only that, but the US proconsul Paul Bremer then decided to disband the largely Sunni Iraqi Army, instantly creating 500,000 unemployed Sunni men, now armed and angry, and then discriminated by their very own Shiite majority, thanks to US stooge PM Maliki. That was the seed for the creation of ISIS.
This mess thanks to the greatest foreign policy blunder ever made by a US administration: Dubya's invasion of Iraq under false pretenses. 3 trillion dollars spent that resulted in 4500 US service persons killed, and over 1 million Iraqis dead, all for nothing, plus the creation ISIS.
And that's not all. Hilary Clinton decided that Assad would easily go, and when he didn't, undertook the destabilisation of Syria through the funding and arming of terrorist groups either directly (Free Syrian Army) or through its proxies Turkey, Qatar and Saudi Arabia, of al-Qaida/Jabhat Al Nusra and ISIS. The US ambassador to Libya was killed while arranging the transfer of weapons from Libya's vast stores to Syria to fuel the foreign jihadists there.
So no. It didn't happen because they've been fighting each other for 1500 years. It happened because of foreign western interference in the region that dates back to at least a century. The blowback is ISIS, plus millions of refugees undermining the very fabric of Europe as a result of fleeing war caused by the West because it just can't keep its hands off ME oil.