(CNN) -- Last week, Iraq's second-largest city of Mosul fell to the Islamic State in Iraq and Syria, or ISIS. In a few hours, the city's security forces had dropped their weapons and uniforms and fled. Since then, the militants introduced a political charter in Mosul and marched south, seizing additional towns en route to the capital, Baghdad. In taking Mosul alone, ISIS gained as much as $425 million in cash, an unspecified quantity of gold bullion, huge amounts of light and heavy weaponry (mostly U.S.-made) and probably hundreds of new recruits from three main detention centers, all which were overrun.
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Charles Lister: ISIS gaining recruits, cash and weapons in inevitable offensive in Iraq
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Lister: ISIS gains from what has become a Sunni uprising, but its ties to Iraq's Sunnis unstable
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He says once ISIS brutality starts, support may change and ISIS will be forced back
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Lister: ISIS a formidable, fanatical force bent on rapid results but may fail in long term
Mosul
Mosul
Mosul
ISIS has substantial roots in @placeholder, where it managed to remain a potent force during and after the U.S. troop "surge."
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ISIS
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Mosul residents might be praising the current stability and @placeholder-subsidized bread and fuel prices, but once the public flogging, amputations and crucifixions begin, this may well change.
Iraq
Iraq
Iraq
Iraq
Last week, the @placeholder insurgency was just that, an insurgency.
U.S.
In addition to massive quantities of small arms and ammunition, this latest offensive has seen ISIS reportedly seize dozens of U.S.-made armored Humvees and military transport vehicles, @placeholder M198 howitzers and possibly even helicopters.
Iraq
Iraq
Iraq
Iraq
There can be no underestimating the impact this will have upon @placeholder instability.
Mosul
Mosul
Mosul
Within 12 hours of seizing @placeholder, there were reports that ISIS transferred Humvees, manpower and other weaponry into eastern Syria.
Baghdad
Considering recent events and its march to @placeholder, this objective might not be so inconceivable.