Story highlights David Patrikarakos: Defeating ISIS means, above all, winning the narrative war

The ability to stream events in real time on platforms such as Facebook is vital, he says

David Patrikarakos is a contributing editor at The Daily Beast and author of a forthcoming book on social media and war. The opinions in this article belong to the author.

(CNN) If the 21st century has taught us anything, it is that to fight a successful war an army needs a successful exit strategy. Bereft of one, while it may win the military battle, it will ultimately lose the strategic war.

Nowhere is this aphorism clearer than in the cases of the post-9/11 conflicts in Afghanistan and Iraq. In both cases, the US-led coalitions -- especially in Iraq -- won an easy initial victory against their adversaries. But the defeating of Saddam Hussein's army proved to be merely the beginning, not the end, of the real war in Iraq.

This week, something almost unprecedented happened. Viewers could watch, via a live-stream on Facebook , as Iraqi-led coalition forces began their campaign to retake Mosul from the terror group ISIS. It was ISIS' capture of Mosul , Iraq's second-largest city, that allowed its leader, Abu Bakr al-Baghdadi, to declare the restoration of an Islamic caliphate across large swaths of Iraq and Syria in June 2014.

Live-streaming a military operation has obvious disadvantages, not least militarily. Why, for example, would you allow your enemy to see what you are doing as you prepare to storm its stronghold?

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The answer lies at the heart of modern warfare. In the 20th century, wars were most usually fought among states. In the 21st century, the biggest challenge is asymmetrical warfare: Nations now fight against insurgent groups.

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