Earlier this month, we brought you an in-depth look inside Islamic State’s sprawling propaganda machine.

As outlined extensively by Charlie Winter in a study entitled "Documenting The Virtual 'Caliphate'”, ISIS produces nearly 40 pieces of propaganda each day in various formats ranging from video, to print, to radio.

The workload is divided between dozens of individual production units hailing from all corners of the caliphate from Libya to Raqqa to Mosul. Here’s Winter’s org chart which shows how each discrete unit fits into the larger picture:

And here’s how each of the various “Wilayats” contribute to what is truly an impressive effort in terms of output:

As we discussed, Islamic State's propaganda machine is a critical part of the group's highly successful recruiting efforts. The following graphic should give you a decent idea of how many foreigners have traveled to fight with Islamic State in Iraq and Syria:

(Source: Soufan Group)

Put simply: recruitment on that scale would be all but impossible in the absence of the al-Hayat Media Center and its myriad offshoots.

Importantly, ISIS propaganda isn't limited to murder montages. In fact, quite a bit of Islamic State media focuses on portraying life in the "caliphate." The idea, of course, is to project some semblance of normalcy - to show potential recruits that a society governed by Sharia Law can still have the trappings of modernity. Here's a breakdown of ISIS propaganda by topic:

Given all of this, one would certainly think that the US would be interested in dismantling the network that serves as Islamic State's recruiting arm. After all, if the group can't replace the fighters killed on the battlefield, its ranks will shrivel. As it turns out, the US has "spent months" mapping the locations of the various media production units shown in the org chart above. Despite knowing their locations, Washington has refrained from destroying them - supposedly for fear of inflicting civilian casualties.

Here's The Washington Times with more:

Intelligence officials have spent months mapping out known physical locations of media safe houses where the extremist group’s operatives are compiling, editing and curating raw video and print materials into finished digital propaganda products for dissemination across the Internet.

Most of the locations are embedded in heavily residential areas in Syria, Iraq and Libya and are not being targeted by U.S. airstrikes because of Obama administration concerns about civilian casualties, according to sources who spoke to The Washington Times only on the condition of anonymity.

Critics, including a growing number of lawmakers on Capitol Hill and some current and former officials directly involved in the project, say the administration’s effort is badly mismanaged and underfunded, allowing the Islamic State to maintain a physical footprint of media production houses upon which creation of the terrorist group’s most influential products depends.

The propaganda operation’s vastness and sophistication are considered unprecedented in Islamic terrorism. Although its penetration across the Internet relies on a seemingly endless spray of links posted by the Islamic State on social media sites, it is the core media products that such links lead back to that analysts describe as most worrisome.

Twelve issues of the group’s official propaganda magazine Dabiq are now online in several languages, including Arabic, English, Russian, French and Turkish. The shiny content, organizational integrity and layout are more thorough and professional than those of many American newsmagazines.

More striking for the visually driven young audience are the dozens of highly curated recruiting videos that Islamic State operatives have produced using elaborate graphic animations, special effects, live-action speed edits and Hollywood-quality voice-overs.

As The Times goes on to note, "the notion that U.S. officials possess such information is confounding to some analysts."

“Obviously, if we know where they’re producing the propaganda, we should be doing everything we can to destroy their facilities,” said William McCants, a Brookings Institution scholar and former State Department senior adviser for countering violent extremism.

Yes, "obviously." Just like the US should "obviously" be destroying the ISIS oil convoys which help the group generate between $500 million and $1 billion per year in revenue. Of course the argument for not striking the oil trucks is the same as that outlined above for not hitting the media production centers: collateral damage.

So ultimately, the two most important pieces of the Islamic State puzzle are the illicit oil trafficking business (that's where the money comes from) and the propaganda machine (which serves as the group's recruiting arm). The US could, if it chose, eliminate both but refuses to do so out of respect for the civilians who might perish in the mayhem.

As we discussed in the context of the oil convoys, it seems rather odd that The Pentagon, which just two months ago fired indiscriminately on an MSF hospital in Kunduz killing dozens of civilians, and the CIA, which runs a drone program that misses its intended target 90% of the time on the way to claiming countless innocent lives, is suddenly so concerned about collateral damage that the US is helpless to stop Islamic State from getting rich both in terms of blood money and in terms of recruits.

Those of a skeptical persuasion might be inclined to suggest that the US is deliberately keeping the media units operational just as Washington has avoided hitting the oil convoys. After all, if Islamic State stops recruiting, they may disappear and if the public is no longer subjected to Hollywood-esque executions filmed in sparkling 1080p, Americans may forget why the US needs to be in Syria - and we can't have that.

On that note, we'll close with a quote from an unnamed official who suggested that the US needs to keep the ISIS propaganda machine operational so Washignton can "learn" from it.