Riven by religious extremism and brutal sectarian competition, Iraq is descending again into the madness of civil war. The Maliki government has made a mess of things since taking office, estranging large segments of the Iraqi population along the way. The U.S. contributed to the mess via its hasty withdrawal two years ago, electing to end its security mission based on the Obama Administration’s desired timeline instead of as a response to achieving specific security objectives in Iraq.

Continued military involvement in Iraq would have entailed bitter costs in terms of manpower, treasure and casualties. But it also would have the benefit of giving the U.S. more influence over the behavior of the Iraqi government. A continuing military presence would have enabled the U.S. to intervene where necessary to manage tensions among competing Iraqi elements, mitigate the influence of Iran, assist the government in quelling unrest at its earliest stages, develop high-fidelity intelligence that supported all the preceding items, and maintain options useful in future situations which, inevitably, develop over time.

In short, being there helped to keep a lid on things, and when problems did develop, let us address them more quickly and effectively. With all U.S. forces gone, however, the President has very few options available. And, as the current crisis continues to unfold, the few remaining options are almost uniformly bad.

Just what options might be available to President Obama if he is forced to act to salvage what can be saved of the elected government—and the hard-won gains that cost America so dearly over a decade? And what would be the pros, cons, and challenges for each? Keep in mind that, as a consequence of fully withdrawing U.S. capabilities in late 2011, the military would be effectively starting from scratch as it moved to mobilize, deploy, and receive into theater the necessary forces—along with all the requisite logistical support—if directed to pursue any of the options discussed below.

Intelligence, Surveillance, Reconnaissance (ISR):The simplest type of support from a ‘no boots on the ground’ perspective. Enhancing Iraq’s understanding of ISIS force disposition, movements, and planning efforts could markedly improve things for the government in Baghdad. U.S. technical capabilities far surpass those of Iraq, so this could provide a significant asymmetric advantage.  But, it begs the question of whether Iraq can get its act together sufficiently to field forces capable of using the information and willing to engage ISIS forces. Reporting so far indicates Iraqi units are simply ceding ground without a fight, in some cases turning over weapons, supplies, and equipment. Another possible downside to this option:  the security risk of sharing such information.  The information itself can sometimes reveal sources, methods, and capabilities the U.S. might not want others to know about.

Advisors: Deploying a small number of highly skilled advisors could likewise have a substantial impact on the effectiveness of anti-ISIS operations. But, like ISR, it presumes you have someone to work with. Placing U.S. forces on the ground, however few, carries the risk of casualty or capture.  The latter poses a significant political risk. The personnel likely tapped for this type of mission are specifically trained for such work, but placing any U.S. military personnel on the ground effectively recommits the U.S. to helping solve Iraq’s troubles.

Supply and materiel: Food, medical supplies, possibly ammunition are all relatively easy to ship to a partner.  It would be a material gesture of support, and the cost is minor, compared to the deployment of actual forces. But like ISR, advisors, or any other type of support not involving the use of U.S. military units operating as independently capable combat elements, one has to question just how much an offer of supplies would help the Iraqi government defeat its enemy. If Iraqi units are unwilling to take a stand, the supplies and materiel could easily wind up in ISIS hands.

Major end items: We’re talking trucks, generators, perhaps engineer equipment or (less likely) communications gear or specialized computer suites that help commanders coordinate force activities. Trucks and such are easy to operate, but to keep them going (especially in a combat environment) requires parts, supplies, and technical expertise. High-tech equipment like communications gear raises the support requirement still further. And, again, there is the risk of such items falling into the hands of the enemy.

Combat vehicles and heavier weapon systems: Providing “lethal aid”–i.e., armored vehicles, tanks, rockets and missiles, heavy machine guns, and other items that can be used to kill enemy forces–ups the ante even more. Unless accompanied by U.S. personnel, sensitive and/or top-grade combat equipment would be simply turned over to forces who may not know how to use it effectively (if at all), with the same potential for downstream acquisition by the enemy through capture, surrender or abandonment.

Specialized capabilities: These would be items or people of an especially sensitive nature either because of special skills, the materials employed, techniques or knowledge necessary for use, or that carry special political sensitivity. Necessarily, support of this type would carry with it due consideration for all the risks and benefits that pertain to use in the context of Iraq’s crisis.

Airlift: The U.S. strength in this area is unrivalled. Moving units or supplies from one place to another by air is routine for the U.S. and would be a boon to the Iraqis. But, it would also place U.S. personnel and expensive, limited-in-number aircraft into a combat zone without the air defense or fire support assets that would normally accompany such operations with the U.S. in the lead.

Strike support (air, land, or sea-based): Most commentators discussing support-to-Iraq focus on “fire support.”  This can be in the form of bombs and missiles from aircraft (manned or unmanned), short range guided rockets/missiles, or longer-range missiles launched from sea (ships or submarines). Aerial-delivered fires carry the risks of transport aircraft, i.e., being shot down if the enemy possesses anti-air capabilities. It also presumes airfields close enough to deliver a meaningful level of strike support in a timely manner. Land-based airfields brings up the question of nearby countries being willing to support such operations from their soil. Sea-based support presumes maintaining sufficient carrier presence in the region and the aerial refueling support necessary to sustain such operations. Land-based fires are much more problematic, given the question of “where” the ground unit would be located. The U.S. has long used unmanned aerial systems (drones), so this might be the most naturally appealing option. But in all these cases, dropping a weapon onto a target requires proper target identification and the ability to direct the weapon onto the target. This can be done in various ways, but all demand a level of involvement in the conflict that minimizes the chances for mistakes or for U.S. lethal fires to be exploited for political purposes by the government we would be supporting. In any case, this makes the U.S. an active participant in the battle against ISIS.

Security/enabling missions: The Administration could offer U.S. military forces to take up the task of securing key Iraqi government facilities, resources, or towns in order to free-up Iraqi units for battle. But like the option that follows, the means a decision to re-introduce U.S. ground forces into Iraq, something this Administration, Congress, and even the American people seem loath to do.

Ground combat and combat support units: This would be the most intense form of U.S. military assistance to Iraq—a decision to re-engage in active combat operations in Iraq. Though it would likely be the most effective option to combat ISIS forces, it carries the greatest cost in all forms and would place the U.S. back in the dilemma of determining when conditions warrant withdrawing troops again.

Clearly the President has a range of military options available if it becomes necessary (or desirable) to help Iraq combat ISIS. However, each option carries not only a cost but the critical questions of relevance and consequence. Ultimately, provision of any support rests on the political calculus that should prioritize the security interests of the United States over those of Iraq-proper. Is it in America’s interest to help the Iraqi government defeat the forces of the Islamic State of Iraq and the Levant? Once that question is answered, and the level of importance determined, then the Administration and Congress can sort through the matters of acceptable risk, cost, and extent of U.S. involvement.

 - Dakota Wood is The Heritage Foundation’s senior research fellow specializing in defense programs.