• The Turian Hierarchy - The turians are the greatest threat to Alliance interests. While the batarians are more openly hostile, they are a second-rate power. The Hierarchy is powerful, stable, and proactive in suppressing perceived threats. There is continued friction between jingoistic human and turian organizations, who wish to "settle" the diplomatically-resolved First Contact War.
• The Asari Republics - The asari are a moderate threat to Alliance interests. Their economic power and diplomatic reputation allow them to wield persuasive influence. Fortunately, their military is barely more than a collection of local warrior bands. Soldiers are well-armed and exceptionally skilled, but do not possess sufficient organization for large-scale military campaigns.
• The Salarian Union - The salarians are considered a moderate threat to Alliance, but share certain similarities in mindset. They are politically liberal, often at odds with the conservative turians and centrist asari.
• The Illuminated Primacy (Hanar) - The hanar are an inoffensive third-rate power, and considered a minor threat to the Alliance. They have little interest in interacting with other cultures, due to a cultural obsession with manners and politeness that verges on monomania.
• The Vol Protectorate - On their own, the volus are a minor threat to Alliance interests. However, several hundred years ago they became a turian client race, exchanging their mercantile prowess for turian military protection.
• The Courts of Dekuun (Elcor) - While the elcor are territorial about any area they consider theirs, they have no interest in aggressive expansion. They have a small military and are no threat to Alliance interests.
• Quarian Migrant Fleet - The quarian Migrant Fleet includes several hundred warships, but due to their precarious existence, cannot be considered a creditable threat. The quarian military does not attack others; it defends the Fleet. Thus far, the Alliance has not been required to block quarian access to human-claimed systems.
• Keepers - The "keepers" of the Citadel are not considered a threat by Alliance Intelligence. They appear to be genetic constructs, simple-minded biological androids created by the Protheans to maintain the structure of the Citadel station. When the asari discovered the Citadel, the keepers were already doing their duties. They continue to do so to this day, following apparently-instinctive routines and blithely ignoring the millions of aliens that have settled in their home.
  

There is no known way to communicate with the keepers. Attempts to take them into custody for study cause the creatures to undergo a sudden "self-destruct," with a form of acid being released internally. The affected keeper literally melts into a puddle of proteins and minerals in less than a minute.

No matter how many keepers die due to old age, violence, or accident, they maintain a constant number. No one has discovered the source of new keepers, but some believe they are grown deep within the inaccessible core of the Citadel.