As the world continues to debate the prudence of military intervention in civil-war-ridden Syria, the United States will continue its own discussion as to whether the Syrian rebels are a force worth being reinforced. While we’ve heard plenty on what Syria President Bashar al-Assad and his regime have subjected unarmed civilians to and why the U.S. is considering some form of mediation, we haven’t heard much about the oppositionists and the groups that comprise them.

The media has portrayed the Syrian Civil War as a gory campaign having most recently culminated in the August 21 chemical strikes on the suburbs of capital city Damascus, and rightfully so. That particular strike resulted in the death of at least 1,429 innocents, including 426 children. But who’s standing up for these people? Who are those that are taking the battle to Assad’s enormous doorstep? Here’s a quick guide to understanding who the Syrian rebels are.

The U.S. debate

Yesterday, Secretary of State John Kerry told the House Foreign Affairs Committee that he expects around 15 to 25 percent of the roughly 70,000 to 100,000 strong rebel force to belong to “one group or another who are what we would deem to be bad guys.”

Michael McCaul, the U.S. Representative for Texas’s 10th congressional district, volleyed back at Kerry saying as much as 50 percent and rising of the rebels are, or will soon be, affiliated with groups related to al-Qaeda. He continued by citing a classified briefing on the situation strictly for congressional eyes that, “every time I get briefed on this it gets worse and worse, because the majority now of these rebel forces – and I say majority now – are radical Islamists pouring in from all over the world.”

The main concern is that the United States will take up arms with known terrorist associates to overthrow a dictatorship only to then place the government in the hands of those our nation has spent time, money, and American lives trying to retract power from.

Nusra Front

The Nusra Front’s stated goal in the revolution is for “the fall of the regime” but they’re still considered a foreign terrorist organization by American standards. With 7,000 followers and boasting the description of being “the most aggressive and successful arm of the rebel force,” the Nusra Front are thought to be led by Iraq-based jihadist al-Qaeda members and are considered the best trained and most well armed of the group.

But the Nusra coalition, like Assad, is thought to be responsible for the deaths of innocents. And al-Nusra is suspected to be behind two simultaneous bombings in Damascus that killed 44 people and wounded 166 in December 2011, adding to its portfolio of suicide bombings and car explosions.

Syrian Muslim Brotherhood

Against the Syrian government from the start, the Muslim Brotherhood in Syria can be looked at as an ally against the national government. This group has had a rift with the Ba’athist regime reigning over Syria since it staged a coup in the early 1960s, being subjected to discrimination and persecution tactics along the way. Things aren’t much different today.

In April 2012, the Brotherhood in Syria called to “establish pluralism and democracy in a civil constitutional State, with equality of all citizens” once Assad is removed from power. They are now regarded by the Syrian government as having escalated the conflict to its current state.

Supreme Military Council & Syrian Opposition Coalition

The SMC and SOC “co-signed a document determining that the organizations’ objective was the fall of the regime … At the end of february 2013, Secretary of State John Kerry announced that the US would provide non-lethal support to the SMC, via the Coalition. Thus, the relationship has produced material aid to the SMC.”

Essentially, these two groups are working in tandem to secure foreign aid to help their cause. SOC secretary-general Mustafa Sabbagh has personal ties to the Muslim Brotherhood, having distributed Muslim Brotherhood funding to the Syrian opposition during the early days of the rebellion, further bolstering his position as a valuable asset to the revolutionary cause.

Free Syrian Army

The  non-sectarian Free Syrian Army is the umbrella group under which all others operate. Roughly 80,000 strong, the FSA has been instrumental in rebuffing attacks by Assad and consolidating rebels under a single banner. A major issue with the FSA appears to be leadership and organization.

Without any real direction, the disorganized nature of the FSA has allowed for the likes of al-Nusra to stake a claim in the civil war and spread their own respective influence. Because of its secular stance, the FSA is often subjected to internal disputes among the more radical and religiously-minded, weakening its general position in that regard.

Bottom Line

It’s nearly impossible to say how, exactly, the Syrian rebels can be defined because they’re too eclectic and nebulous in breadth and scope. CNN reported on the air Thursday that some 1,200 different groups comprise the rebels, and not all are going to have the United States’ best interest at heart. This is a major concern for those still undecided on Capitol Hill, because quite simply not all rebels can be accounted for, with some nervously aligning with terrorist organizations who offer hope, however misinformed, to the weary. As we stand, there are so many rebel groups, it can be hard to pinpoint what, exactly, each are fighting for.

A video obtained by the New York Times shows what’s thought to be Syrian rebels brutally executing nationalist prisoners. Available to watch below, the clip is graphic in nature. However, it depicts some of the greatest fears congressman face as they weigh the option of intervention: namely, that while consolidated, some rebel groups are more aggressive and extreme than others and can possess the conviction of putting their own agenda ahead of their people’s.

WARNING: This video is graphic in nature.