Iraq is facing its gravest test since the US-led invasion more than a decade ago, after its army capitulated to Islamist insurgents who have seized four cities and pillaged military bases and banks, in a lightning campaign which seems poised to fuel a cross-border insurgency endangering the entire region. The extent of the Iraqi army's defeat at the hands of militants from the Islamic State of Iraq and Syria (Isis) became clear on Wednesday when officials in Baghdad conceded that insurgents had stripped the main army base in the northern city of Mosul of weapons, released hundreds of prisoners from the city's jails and may have seized up to $480m in banknotes from the city's banks. Iraqi officials told the Guardian that two divisions of Iraqi soldiers – roughly 30,000 men – simply turned and ran in the face of the assault by an insurgent force of just 800 fighters
Iraq army capitulates to Isis militants in four cities | World news | The Guardian
This is extraordinary. However, these people are so extreme (they were expelled from Al Queda!) that only a fraction of the population will support them. It's not widely appreciated that before the West had to deal with it (after 9/11), Islamic extremism tried for at least a decade to get hold in quite a number of countries (most notably Algeria) and they basically failed as a large part of the population simply doesn't subscribe to their ideas, much less their violence.
But that's about the only upside here.
There needs to be an army willing to fight them and there are no easy or palatable options. Realize that the main guy fighting them is Assad...
Perhaps the Turks will get in after the kidnap of 80 of their citizens (many from the Mosul consulate), but even that would be a distinctly mixed blessing as for sure the Kurds in Northen Irak would not like to see that happening.