Here is what the media had to say about the fall of the Iraqi city, as per a BBC report:
Al-Mada (Iraq): "Mourning Iraq, mourning Mosul, mourning Falluja, mourning Samarra, and mourning all the other Iraqi cities which will fall to the ISIS, one after the other... Saddam Hussein and the Baath Party destroyed Iraq and left it as only a half state. Political Islam is now destroying the other remaining half of the state."
Al-Mada: "What really happened? Why was the road so clear for all these mercenaries to march in?... How did the group reach the outskirts of the city, then its very heart, without having been at least intercepted by the armed forces? Why was air power not used to deter or to paralyse them, if not to eliminate them altogether?"
Al-Watan (Saudi Arabia): "The Iraqi prime minister's endeavours to cling to power at any cost are nothing new... For his top commanders to flee the clashes and to refrain from protecting civilians in Mosul suggests two things: restlessness, or a desire to shuffle the cards - which is far worse. Paving the way for ISIS to establish control over the Sunni city of Mosul arouses suspicion."
Observers feel that Iraq could be destroyed if no action is taken now
Al-Dustur (Jordan): "The state is crumbling in western Iraq and Iraqi cities in Sunni provinces are falling one after the other... As for us in Jordan, we no longer have the luxury of wait and see, because the danger is approaching our bedrooms."
Javan (Iran): "Daesh's movement in Iraq is the growth of the cancer of terrorism in that country; and Iraqi leaders, including Shia, Sunni and Kurdish, should quickly take measures to eradicate it. Otherwise, this cancer will swallow the whole of Iraq and even the region".
Tishrin (Syria): "With bloody extreme-Islamist developments sweeping Syria, Iraq, Yemen, Libya, Egypt, Tunisia and other countries, the Arab street, the elite in particular, and intellectuals across the world are now convinced that Arabs will have no stability while the Saudi royal family exists."
Al-Hayat Al-Jadidah (Palestine): "Daesh and its actions in the Iraqi province of Nineveh should be a lesson to everyone around the world. This was the result of Shia oppression supported by Iran, which triggered the anger of the Sunni minority".
Milliyet (Turkey): "The ISIS threat and the probability of an expansionist Salafist state reaching from Syria to Iraq require Turkey to reconsider its strategic priorities. And unexpectedly, Ankara finds itself on the same side against al-Qaeda as Iraqi Kurdish leader Massoud Barzani, the Kurdistan Workers' Party (PKK) in Turkey, the Kurdish Democratic Union Party (PYD) in Syria and Iraqi Prime Minister Nouri Maliki, whom it does not like at all."
Yeni Safak (Turkey): "One should not underestimate ISIS. It could be a strategic mistake to characterise it as a marginal terrorist organization in the al-Qaeda category".