Given that the Federation defeats the Borg in every encounter they have, why do the Borg always only send one cube to challenge the Federation? They're pretty smart, you'd think they'd figure it out after the Best of Both Worlds arc that the Federation wasn't to be trifled with and send more than one cube in First Contact. Is there ever an explanation given for why they don't do this?
I'm sorry? In what way were the Borg not successful? They sent one cube, it broke through all of the Federation's defenses, reached earth, dropped its payload and converted the entire planet into a Borg hive many years in the past.
It was only via a fluke that the Enterprise was able to follow them and stop them. And they only just barely managed that.
They even took their queen with them in order to temporally duplicate her. Sounds like a pretty sound plan to me.
The only problem I see is that they waited to the last minute to travel back in time, if they had done so before reaching Federation space, they would have defeated them before they existed. But that would have made a pretty crap movie.
This gives me a pretty good idea, especially the first sentence.
In terms of offense and defense, a Borg cube is a fleet in and of itself. Common capabilities of cubes include high warp (transwarp) capabilities, self-regeneration and multiple redundant systems, rapid adaptability to almost any assault (though not complete immunity, in Star Trek: First Contact it's shown that sufficient firepower from Federation ships could still destroy a Borg Cube after it adapted to their weapons), and various beam (tractor beams and cutting beams) and missile weapons. A single Borg cube has, on multiple occasions, taken on entire Federation fleets and held its own. Cubes have been commonly known to carry sphere ships in cavities covered by large slide-away hatches in the outermost layers.
I think it's hard to argue with that and that's a pretty rational explanation. Remember, the Borg won at Wolf 359 (admittedly, with Locutus/Picard's help).
The Borg aren't as concerned about immediate results as humans. The Collective marches on toward assimilation of all life forms, but it has no desire to do so at any particular pace.
There is no individual ego pushing to get it done in one person's lifetime. There is no one to get impatient or anxious. The Borg continue to do what they do, confident that their assimilation of the Federation will succeed. Maybe not this time, but they will succeed. And of course, losing ships and lives along the way is of no consequence to the Collective.
- The Borg do not conquer
- The expeditions to the delta quadrant are "reconnaissance in force" missions, not invasions.
- The Collective is a large distributed network
- the Collective still has communications time-lags.
- Borg are Overconfident
- Individuals and Cubes are expendable
The Borg Do Not Conquer
The evidence in Voyager is pretty darned clear - the Borg are not conquerers in the sense that we think of, say, the British Empire.
We know the Borg are not terribly innovative; they brute force solutions. They rely upon others being innovative and then capturing and assimilating knowledgable technicians.
Assimilation of worlds allows a massive data dump, and a large new population from which to staff a new location, but, fundamentally, it's a process much like a viral infection - they have no real desire to kill the host, just to turn the host to replication of the virus.
Reconnaissance In Force
A tricky military concept, the Reconnaissance In Force (RIF) looks like a small scale invasion to the inexperienced eye. It isn't. It's a very thorough attack, calculated to find the strengths and weaknesses of the target.
That's exactly what the sequence of cubes seems perfect to do. Find out what the strengths and weaknesses are of the Federation. They find out that the Federation is big enough to be a threat, but not technologically advanced enough to be a major threat. By poking them with a cube, it also provokes strategies to overcome them, and projected solutions to those strategies. If the cube can assimilate some or all of those strategies, the RIF has had a tech success even as the cube is lost.
We see this in the continued improvements in adaptation time.
The Collective is Large and Distributed
The Borg are not actually all that centralized. They rely upon localized assets making decisions. Until the threat level was established, the collective could not see making a major bid to tackle the Alpha Quadrant. They were, in a word, busy. Busy being Borg in the Delta Quadrant. Busy fighting Species 8472. Busy collecting new developments from the stragglers of assimilated races.
A cube or 5 isn't a big expense, per se. They are capital ships, for certain, but the borg could, in theory, rapidly build a dozen for a fleet. But that dozen would be better used elsewhere, until the failures of the Time Sphere at Earth.
The local command node probably couldn't afford to send more than one at a time. While the collective could, the local node can't. It's got other fish to fry - establishing a secure base near the Alpha Quadrant, and poking all the locals.
They probably even calculate that they're being subtle.
We know from Voyager that the communications network is fast, faster than the Federation's, but still not instant. And, like any hierarchy, information gets filtered. Local failures thus take time to become important enough to be passed upchain, and once passed, still take time to reach headquarters.
A Cube might be a single "hive mind", but the sector node is a collection of short-lagged ones. We see this effect in several episodes in both TNG and Voyager - present a small enough threat, and you don't get reported until after the assimilation... or its failure.
Borg are Overconfident
We see, in every encounter, that the Borg consider themselves, as a collective, the superior civilization. They have an overconfidence that is well earned. They inherited it as part of their developmental path, and it served them well enough, so well that it became part of the core Borg identity. It's only finally hit major challenges with Species 8472 and with the Federation.
Individuals and Cubes are expendable
The Borg consider individuals, and even any single cube, as a resource - one to be expended in gaining information. The Borg have only two real goals - information gain and continuation. These lead to secondary goals - security, threat assessment, force projection, and target selection.
What This All Means
Until the Federation proves to be a threat, they are more useful for being innovators, rather than being bulk assimilated. The first cube at Wolf 359 is a test, not a real invasion. The threat of assimilation was very real, but it was more a test of if Picard's own arrogance about the Federation was worthwhile.
It was. As a reconnaissance, it worked. It showed the Borg that, if they needed to, they could just overwhelm the Federation with numbers; something that they couldn't do with 8472. Again, overconfidence in setting their simulation parameters. By the time they realized they had been overconfident, it was time for a new, and more drastic plan.
Further, it set the federation a technical bar to overcome, one that would make their later assimilation more worthwhile. Keep poking until it becomes apparent that they have a new technology to be assimilated.
The Federation didn't rise to the bar - they found the weaknesses in Borg Society and exploited them, rather than looking into new technologies.
The Time Sphere isn't really about assimilation - it's about preventing the Federation disruption to their own culture. It is about not letting Hugh and 7 of 9 lead rebellions. It's about retaining internal control - because that's the one thing the Federation attacked, time and again.
The collective as a whole was not bothered by the loss of the queen in the movie. The Time Sphere was shown to be expensive, and may have been a regional level decision, not a collective-wide one. In any case, it was a response to the the Federation threat to their cultural integrity, not a military threat.
As to "Why at Earth?" probably because they were looking at the time distortion, fine tuning for a period before radio, but not before manufacturing. A time when the drones they will make will be suitably minded to adapt to tech, but not sufficiently advanced as to be able to resist or understand the computer networking until well integrated. It's easier to do that if you are in scanning range.
The Borg are obsessed with efficiency and in "Endgame" it is revealed that the trans-warp network the Borg have contains only exit apertures in the Alpha quadrant. Assembling an armada to shatter the Federation would be stupid because it would not be practical to get needed drones/ships/general supplies back to the collective heartland in the Delta quadrant using ship-borne trans-warp drives; the trip would take months/years and the Borg would likely take losses along the way back. The Borg are also aware that the Alpha quadrant is not likely to have technologies that the Borg can assimilate to help them achieve a more desirable level of logistical organization. Furthermore, if a large Borg presence near earth became known to the major powers of the Alpha quadrant, the isolated Borg fleet would almost certainly be surrounded and obliterated by a large combined force of ships from the Klingon, Romulan, Cardassian, and other nations. The Alpha quadrant powers would also probably assemble massive a fleet to guard the trans-warp aperture from future attacks. This whole scheme would be a disaster for the Borg. That's why they never sent more ships. The likelihood is the Borg will keep conquering in an outward style from their home in the Delta Quadrant until the Borg "border" the Federation. Then it would be much easier for them to conquer the Federation and the Alpha quadrant.
The one cube was most likely sent in an effort to destabilize the Federation. No doubt the Borg probably do that to other peoples around the galaxy before they reach them with a more sustainable, larger force, just as I explained up there. They would probably keep sending ships to destabilize the Alpha quadrant, little by little, before they assaulted them.
Sabotage via trans-warp network. Not overthrow.
I believe that not a single episode or movie explains this (excuse for poor) strategy
, but the corpus around the Borg, up to Voyager, provides some clues to that.
I believe distance is mostly to blame. Before Voyager came out, very little was established of transwarp conduits, and so the general plotlines followed along the idea that Borg cubes came out of the depths of the Delta Quadrant, and thus took a generally long time to get reach the Earth.
Plus, plot-wise, defeating a single Borg cube was hard enough, sending in dozens on the second round only to have our heroes beat them (for the sole purpose of them having to win in the end :P) would seem far fetched.
Other works of sci-fi have used similar devices where a first conquest task force is sent ahead of a larger colonization one.
There's also another factor: The Borg collective is a wide ranging "empire" of sorts. Borg space spans thousands of light years. They're potentially stretching their resources to the limit. Hence, perhaps they can only afford to send one ship at a time.
So you're looking for a "in-Universe" answer, not a "because it fits the story" answer. In Voyager at various points groups of cubes are observed, a large number against Species 8472 and a larger number guarding their hubs. Even in the "home space" area of the Borg multiple cubes are rare, so it seems reasonable that it takes a lot of resources to construct & man a new Cube. Considering the defeats the Borg have suffered at the hands of the Federation(really at the hands of just 2 particular starships) perhaps the Borg have decided that they are too powerful to engage with at the moment, and have devoted their resources to consolidating their power-base and figuring out how to beat those pesky Enterprise/Voyager captains. That is the strong implication of the finale of Voyager, where the Borg Queen is obsessed with just getting Janeway.
It may not have been that important to them to conquer the Federation. If they win, great, they have a new culture to eat. If not, it may stimulate Starfleet to develop new defensive technologies (which it arguably did with the quantum torpedo) to make them a tastier meal next time. After all, if need be, they can always send a whole fleet when they really want to assimilate the Federation. And Starfleet has shown itself very capable of innovation compared to most cultures seen in the show.
If the Borg think with one mind, then it's probably a very long-lived one. They may naturally play the long game.
The "in-universe" answer is they only needed one cube. The Federation did not have enough weapons to stop even one cube. One cube would infect the entire Federation one planet at a time and spread like a virus.
But for the plot, just one cube that could not be stopped made the Borg seem very scary.
It seemed overkill. They may have the resources, but the Borg have their hands in many honeypots. Some of the species they spar with undoubtedly required more of their resources to deal with. It doesn't seem that far off in asking why the US military doesn't commit more resources, or the Empire in Star Wars doesn't make TWO Death Stars.