Arachnid Quarantine ZoneEdit
The oldest and longest-running such zone is the Arachnid Quarantine Zone, which is the area of planets infested by Bugs which have not yet been cleared. Travel into the Arachnid Quarantine Zone by civilian starships is strictly prohibited. Travel out of the zone by Arachnid starships is likely to be met with all available force. As the Bugs are pretty much incapable of diplomatic negotiations with humans, the long-term plan is to clear the planets in the Zone of Bugs and open them for human colonization. As such, the borders of the Arachnid Quarantine zone have shifted considerably over the years, as human forces gradually push into Arachnid space and new Arachnid-infested systems are discovered.
After the Caal Invasion and the fall of the Federation, the new Holy Terran Empire continued to maintain the Arachnid Quarantine zone - although not very effectively, as the Bugs siezed several human systems during the Ascension War and two more in the decade that followed, resulting in the Quaratine Zone growing even larger. With the Imperial Navy stretched to its limit regulating the hyperspace trade, an additonal makeshift Fifth Fleet under Admiral Molotok was formed instead from obsolete warships staffed by prisoners and posted in the Arachnid Quarantine Zone with the goal of slowing down the Bugs' expansion.
Other Quarantine ZonesEdit
During the final years of the reign of Arthur Clarke as Grand Council Chairman, both the Jurvain and K'Nes were defeated in war and subjugated by the Earth Federation. As neither species were particularly interested in becoming Federation citizens, and the Federation wasn't particularly interested in HAVING them as citizens, their planets were not fully integrated into the Federation.
The Jurvain's existing core planets were marked off as reserved for the use of those species. Travel by humans to those planets, or by aliens off those planets, was strictly regulated, and severe treaty limits on the military forces the Jurvain could posess were instituted. Tech Infantry and Earth Fleet garrisons were stationed on those planets or space stations in orbit above them to keep an eye on them and ensure that the treaty restrictions were being adhered to.
The quarantine of the K'Nes core planets was slightly different. As the K'Nes considered continued trade with humanity highly important, restrictons on travel and economic interactions were gradually eased. However, one particularly troublesome and useless core system, K'Laek, was quarantined in a fashion even harsher than the Jurvain, including an almost total ban on travel and trade in an attempt to starve the system into submission. Among Earth Fleet spacers, this blockade eventually came to be known as the "Litterbox Line."
With the fall of the Earth Federation after the Caal Invasion, the K'Nes and Jurvain Quarantine Zones are both de facto defunct as both races declared independence and rearmed. Since the Holy Terran Empire considers itself the legitimate successor state of the old Earth Federation, officially, the Empire considers the peace treaties the Federation imposed on the K'Nes and Jurvain to still be binding, and thus considers the Quarantine Zones to still be in effect. However, the Empire lacks the forces to impose the sort of occupation and close blockade seen in Federation days, so they restrict themselves to a purely legal quarantine banning trade and tourism across the borders. On the gripping hand, the large level of autonomy granted to Imperial Houses and the systems they rule, coupled with the starvation of trade since the dismantling of the Jumpgate Network, means that many Houses turn a blind eye to K'Nes and even Jurvain smugglers and traders visiting their system, often rendering the quarantine to be so porous as to be nonexistent.
Season Eight Alternate TimelineEdit
The Middle Kingdom maintained the Arachnid Quarantine Zone, but rarely made any effort to expand into Bug Space. Curiously, neither did the Bugs make much effort to expand into human space during the existence of the Middle Kingdom. Rumors abounded that the Emperor had managed to actually negotiate some sort of deal with the Bugs, a feat not previously thought possible. And although they did not call them as such, the Kingdom's conquest of the K'Nes and Jurvain were carried out in a very similar fashion.
Behind the ScenesEdit
The term "Arachnid Quarantine Zone" of course comes from Starship Troopers.