United States military forces use standard procedures for planning operations against other militaries.  These procedures differentiate between different branches, or units, of an opposing force depending on their capabilities and limitations.  This article presents one such analysis of the Iranian Military, where there are vast differences between the Islamic Revolutionary Guard Corps (IRGC)and the Artesh, or the regular Iranian armed forces.  The article then draws parallels to the planning for Operation Iraqi Freedom that led to the defeat of the Iraqi Republican Guard and regular Iraqi forces.
Military Planning
In order to be efficient and focus the efforts of the military forces, military strategists determine enemy centers of gravity.  “Joint Operational Planning,” the primary source for planning operations in the military, defines center of gravity as “a source of moral or physical strength, power, and resistance.”  Once these sources of power have been identified, planners establish ways to defeat them, aiding US forces in accomplishing the objectives of the conflict.  When properly done, it allows the limited resources of the military to be targeted against the most vital interests of the enemy and, by denying these interests, bring about an expeditious resolution to the conflict.
IRGC vs. Artesh
As with any opposing force, a consideration of Iranian centers of gravity must be done relative to the objectives of the conflict.  If the objective is regime change, critical considerations are the military’s capabilities to defend the regime and “moral forces” that support the regime and provide legitimacy.

With regime change as the objective, military planners would consider the IRGC a center of gravity.  Their land, sea, air, and missile forces; asymmetric warfare capabilities; and burgeoning economic stature make them a source of physical strength for the regime.  The IRGC’s role since the 1979 Revolution in propping up the Iranian government and enforcing the strict “Islamist” aspects of its rule make them a source of moral strength.  The defeat of the IRGC would serve the objective of regime change by denying the regime’s key military strength and lessening its ability to enforce their form of governance.    
While the Artesh may not be considered a center of gravity, they would still be deliberately targeted based on their deployment around key strategic areas and certain capabilities.  If Artesh units were deployed as part of the defenses of Tehran, a strategic target for regime change, those units would be targeted.  The Strategic Air Defense Forces (a separate command within the Artesh) would also be high on the priority list in order to allow air power to operate more freely and prosecute targets as required.
This last capability leads to the next step in scheming against an enemy force: how to defeat an enemy’s center of gravity.  If possible, US forces attempt to avoid engaging directly against an enemy strength (the old adage of “around their strengths and through their weaknesses”).  Thus, military planners look for these weaknesses in order to exploit them — critical vulnerabilities.
A glaring vulnerability of Iranian forces is their susceptibility to air attack.  Defending against air power in Iran is a monumental task: the geography of Iran and the outdated technology employed by Iranian forces make air defense very challenging. This task is further complicated for the IRGC by the structure of the Iranian military, which gives the Artesh command of Strategic Air Defense.  While the IRGC does maintain some of its own air defense capabilities, issues could develop if they need further support from Strategic Air Defense.  In situations such as this, where forces from one branch support those of another, complications can arise.  From critical aspects of coordination, like agreement on tactics and deployment of forces, to mundane matters like keeping the morale of soldiers high by ensuring that they are properly housed and fed by another command, a unit’s effectiveness can be degraded when supporting another command.
In a situation where one branch’s forces are working for another, command relationships must be established and followed.  The best case scenario is that, while rank and status are accounted for, subject matter experts are allowed to employ their assets in a way that maximizes their effectiveness.  All too often this is not done, and higher ranking officials are allowed to overrule those who know best, reducing the effectiveness of forces in accomplishing their missions.  

The command relationship for a situation like this, with the IRGC dependent on the Artesh, is ripe for conflict.  With the IRGC having a higher standing within the military of Iran, their leaders might override supporting commanders from the Artesh’s Strategic Air Defense on how they want air defense assets employed.  This would not only reduce the effectiveness of the Strategic Air Defense but further diminish the support relationship by creating tension and frustration on the part of the air defense commanders.
The Artesh represents a critical vulnerability to the upholding of the regime in two other major ways.  First is their attachment to the people of Iran, not the regime.  If their reaction to the 2009 election crisis is any indication, there are a great many people in Iran who disagree with the current system of government.  Since the Artesh is mainly a conscript force composed of the sons of many of these same protestors, they may be hesitant to defend a regime that they know is not supported by their families.  While the IRGC does receive some of the same conscripts, its senior officers are far more linked to the regime than those of the Artesh, ensuring that they would act in its defense.
A further conflict is the battle over morale in the Artesh.  Constantly receiving less funding and attention than the IRGC must surely have a negative impact on Artesh morale.  While it is unrealistic to expect the Artesh to rise up against the government of Iran and the IRGC, especially in the face of an attack by outside armies, any sizable diminishment in the Artesh, which comprise two-thirds of the manpower and critical capabilities (like air defense) of the Iranian armed forces, would be a difficult blow to Iranian officials.
Lessons from Operation Iraqi Freedom
While military tacticians will insist that no two conflicts are the same, the planning for Operation Iraqi Freedom (OIF) does present some parallels in preparing for a military composed of two very different branches in terms of capabilities, similar to the IRGC and the Artesh.  Military planners identified the Iraqi Republican Guard (IRG) as a center of gravity (some generalize this to “special” ground forces which include Husayn’s militia, the Fedayeen, but I will limit the scope by focusing on the IRG).
Their mandate to destroy political opposition and prop up Saddam Husayn’s regime made them critical to the objective of regime change.  Their sources of strength lay in their better training and equipment relative to the regular Iraqi forces.  The US military clearly designated the IRG as a center of gravity as evidenced by the deliberate targeting and focus of firepower on them.  Close to 80% of coalition airstrikes were directed at ground forces, of which the Republican Guard was heavily targeted, and strikes were planned to prevent additional IRG units from deploying to protect Baghdad. The result was the destruction of the IRG before it could consolidate on Baghdad and provide an effective defense.  The loss of the IRG helped coalition forces take Baghdad, considered a key requirement for regime change.
An excellent example of the deliberate targeting of units like those of the Artesh, due to their deployment in a strategic area, is the United States Marine Corps’ attack against Iraq’s 51st Mechanized and 18th Infantry Divisions in the first major ground engagement of Operation Iraqi Freedom.  With maintenance of Iraqi infrastructure as an objective of Coalition operations, the South Rumaylah oilfields were identified as a key piece of terrain.  The Marines were ordered to defeat the enemy in the vicinity of the oilfields and to seize, intact, the oil infrastructure.  With this as their objective, the Marines planned to defeat the forces protecting the oilfields, the 51st and 18th Iraqi divisions.  These units were not a larger threat than any other regular army units, and were considered to be composed of the same ill-trained and ill-equipped forces.  If they had not been designated to defend the oilfields they almost certainly would have been bypassed by coalition forces, like many other regular Iraqi units, in the race to Baghdad.
Iraq provides other lessons for dealing with units considered less capable like the Artesh. The selective targeting of regular Iraqi units in the race to Baghdad was successful in that Baghdad fell quickly.  But bypassing many of the “lesser” Iraqi units in the rush to Baghdad left many follow-on coalition support units susceptible to attack, the most notorious case being the 507th Maintenance Company’s ambush by Iraqi forces, which killed nine American service members.  The first Persian Gulf War also offers a useful lesson: the requirement of planning for mass prisoners from poorly trained units. The Iraqi army surrendered in droves, and quickly exceeded coalition capacities to handle them.  
Consideration of the Artesh is critical for military thinkers as they develop a strategy against Iran.  Should the Artesh be directly engaged due to their poorer equipment and training?  Which Artesh capabilities will need to be targeted and which units need to be defeated in order to achieve the objectives of the conflict?  Once these questions are answered, military planners would need to develop a plan to defeat all Iranian centers of gravity, including units and capabilities of the Artesh, in order to bring about the swiftest possible defeat of Iranian forces and accomplishment of US objectives in a potential conflict.