Sci-fi Military Tactics and Strategy

In addition to the size of the population and how dispersed they are (if they're all concentrated in one area, presumably near where the colony first landed, you could drop your forces far away and allow them to build up over time, especially if the colonists have limited means to wage war on other parts of their planet with an enemy fleet in orbit).

Similarly, even if they do have a sizable population, are they all loyal to the folks you want to take the planet from? Maybe there's a rebel faction you can back and use their forces as auxiliaries for your guys.

There are many problems with occupation forces, the logistical strain on Earth bound occupations is already big without space travel involved.

It will also largely depend on the level of "fucks given" by the occupation force and the population in occupied territories. Essentially if a the territories are too adamant in giving in to the occupiers, they can prolong the time needed to keep a military force long enough to make it too expensive, forcing the occupiers to leave out of the economical/political wear of keeping an occupation force with no resolution in sight.

The success of the occupation will hinge in how it began, a war of conquest and annexation will certainly see a lot of resistance from the conquered, if the occupiers don't care much for civilian casualties and the civilian population of the conquering nations don't care either, the occupiers can simply rule through force and fear but should be aware this kind of peace can fall at any moment. However if you don't care about how many civilians and resistant fighters die or having their planet intact because you have plans that don't necessarily require a mostly intact native population and you can get away with altering the native population to a more manageable size all the strategy can be summed in two Latin words said to the Romans: Vae Victis.^note Woe to the vanquished/conquered

If the population isn't militarized or isn't nationalistic enough to consider a violent resistance a viable option, the occupation army can act as a benevolent faction or adopt the Roman style of conquest, where you let the conquered have their political and economic freedoms as long as they pay their tributes and get eventually annexed into the Empire. For that to work you will have to act as benevolent as possible otherwise it is a matter of time until people get fed up enough to think that raising arms isn't that bad of an option.

If the occupation is conquering a planet that was already in chaos before their arrival, winning hearts and minds could be done with some nation building, aid programs and providing some normalcy to the occupied population, since people would certainly support anyone who can bring anything resembling safety and stability.

You should also keep both a space borne garrison and a ground based one, a steady influx of manpower to rotate and avoid low morale, lots of boots on the ground because you can be as high as you like but you won't own shit unless you're on the ground, have your forces to be trained for peace keeping, policing and counter insurgency operations and properly equipped to deal with those, which means no super tanks or main battle tanks, no strategic bombers or large air wings of air superiority fighters you will need fast response vehicles like helicopters or the VTOL equivalent, COIN and CAS airframes fast enough and with enough loiter time to provide support, armored cars, APC and IFV strong enough to resist IE Ds but light and mobile enough to negotiate with urban terrain, a very well trained Search&Rescue&Retrieval force for MIA soldiers and a strong medical extraction and treatment operation for wounded soldiers and also you will have to devise plans in order to minimize the repercussions of civilian casualties and collateral damage as much as possible in order to keep both support at the occupied nation and at the homeland.

And actually, here's a thought: You might not even need to necessarily deal with the civilian population to achieve your objectives. If all you need are the resources on the planet, and the present population isn't using much of it (like the aforementioned colony world with the relatively small footprint centered mostly around their landing site), you could just drop your forces on a different corner of the planet and get to work doing what you want to do, while maintaining control of the orbitals (and by extension, all travel between planetside and space).

The locals can choose to deal with you. Or maybe they're really good at farming and don't need food shipped in. As long as they stay clear of you (and this all assumes you picked a spot specifically out of the way so they'd have to try really hard to get in your way), who cares if you control them or not?

Slightly off-topic, but I could've sworn that someone in this thread mentioned a video game series or fictional universe where Space Is Air is a Justified Trope because certain parts of the galaxy/universe operate under a different set of physics that mimics Earth in atmosphere-like flight physics.

Anybody have any clue which series that was?

Ok, let me clarify: The hypothetical planet being invaded is earth like, but mostly land. It has a population equivalent to roughly six billion humans. The locals will need some management early on, but significant resistance is not likely. The society is roughly at Earth's present level of militarization, with a slightly smaller industrial base.

Now to be perfectly clear, I am not talking about force composition or any of the space forces, just the numbers. Approximately how many divisions (A division being a military unit of 6,000-20,000 men and consisting of 2-4 brigades or regiments, as said by the great wikipedia) would be necessary to defeat the military forces of this planet?

There is no actual approximation that could be reasonably made beyond a lot.

Our planets levels of weapons all over the damn place and numerous military bodies is not something you really want to have to slug it out with small forces. Traditionally attackers need 2-3 times their opponents numbers to assault a reasonably defended target. That isn't counting any number of variable factors that could change that for or against either side.

So there really isn't anything to go off of other then other works of fiction. For example the Legacy of the Aldenata series of novels the Posleen invade with millions of combat troops alone.

If you go by our worlds standards the back of the napkin of large military bodies counting, active, reserve, and paramilitary globally. That is for just the top 15 ,by size of military, for the world you are looking at 38,916,337 members of the military.

Depending on the estimate and how effective the logistics are the minimum logistics is typically a full 1/3 of the military. Combat arms are 1/3 to 1/2 depending on the size of HQ/Admin elements.

That is just a sample of the top 15 nations by raw military size. The planet total is higher but there are way too many for me to be willing to calculate it out.

edited 3rd Aug '16 5:00:37 PM by TuefelHundenIV

In Battle Los Angeles the website provides some insight when the Aliens make the seafall stating that something like 27m aliens invaded Earth, it is not known if there is more coming but the situation isn't good for the invaders as their technological gap and doctrine isn't overwhelmingly superior to humanity's.

edited 3rd Aug '16 5:28:23 PM by AngelusNox

So yeah in short a lot.

But not such an insurmountable level that you'd need to start acting like your only option is WMD's and flinging space rocks and other genocidal crap.

Tom: You still don't appreciate just how much it would really take to conquer a world. The nearer to parity in technology and capability the forces get the more costly and difficult it gets.

Unless the invading force has some seriously overwhelming advantages taking the planet is a massive and costly task. So much so that nuking it from orbit is significantly less costly for the attackers by a massive margin in all regards. I will say it once again that if your goal is to just destroy the enemy world nuking them from orbit is not only massively cheaper, it is more efficient, has lingering effects, and will be a lot less costly to the attackers in casualties and expended munitions. If you want to conquer the planet it is going to get really expensive in all regards really quickly.

The baseline numbers of warm bodies needed to take on just the big 15's total military count is between 78 million for low end of double the numbers to around 117 million at the higher end. That is strictly warm body count. That isn't the massive monetary cost of the invasion. That isn't counting what would be for a time a very long logistics chain which is both costly and vulnerable.

That is a straight up numbers for numbers estimate it doesn't count the much higher number of personnel needed to take heavily urbanized cityscapes or assaulting hardened areas. It doesn't even cover the larger number of other losses that any military incurs during an operation.

That doesn't cover the even more extensive cost of now setting up occupation forces for the long term. Never mind the long term costs globally of repairing war damage, building up local presence, and the long time period it will take for local resistance to die down to more regional concerns. That isn't counting political costs, public will power. or the long term monetary bill.

That is also assuming no allies or military bodies are sending their own relief forces to come contest the assault of a settled world which by the way means more costs yet for the attackers who will be expending a lot of cost just to travel there and assault the world.

It really is simpler, easier, and cheaper to just blast the planet from orbit and be done with it.

You forgot one thing Marine. If you're even so much as considering ground forces, it likely means the decision NOT to obliterate the place via WMD has already been made. Either politically or militarily. (Most likely politically.)

Because it means the planet in question holds some form of value that is unique to it such as a working biosphere or developed industry you'd want. If you wanted Unobtainium or some other mineral resource you wouldn't even be there in the first place since you could get it from airless rocks and uninhabitable places. If you were out there just to rack up a body count, you would've already fired your Death Laser or Doom Missile upon the planet and it'd be done and dusted. Not even so much as a consideration for alternatives.

Your forgetting civilian that you have an entire planet and nuking several of the largest casualty inducing points like large cities or heavily fortified points that would be extremely costly to take by other means is still quite likely to leave a significant portion of habitable land space intact. Remember you have an entire planet. That also does not take into consideration short radiation duration but high radioactive lethality options like neutron bombs. Also high efficiency bombs leave a lot less lingering and dangerous material after a few short months and a society that can cross the stars to launch a massive planetary war is unlikely to be overly bothered with radiological clean up. That also leaves room for the other WMD's such as chemical and biological weapons. Something we have considered extensively in this and the equipment thread

Also just because you are considering ground forces does not mean you are aiming for conquest either. There are numerous reasons to send ground forces and still nuke the plane to kill everyone on it after their mission or goal is complete.

Nothing collapses political will like massive casualties and taking too long to achieve an objective. Taking a world like that with your idea will result in large and expensive losses. Then there is the strain on will from the long slow drain type of casualties for after the fact. Public and Political will is also very subject to sticker shock at viewing the cost of such an endeavor.

The total numbers for Earth military as of 2014, is 66,665,700 and that is low balling because it was counted to the nearest 1,000 and all the nations below one thousand were added together for a total of 3,000 more. Which puts the low estimate of double the target planets numbers at 133,331,400 and the high at 199,997,100 for the attackers numbers. That is just the raw basic numbers again it doesn't account for having to take multiple hardened targets or large dense urban areas.

The sheer scope of the logistics chain and cost is massive. The aftermath and long term plan is even more costly. Again I don't think you really appreciate how much cost and effort much such an endeavor would take.

edited 3rd Aug '16 7:54:37 PM by TuefelHundenIV

Only use WMD on key locations, like government locations, let the society fall to the mess of there being no one in charge and people fighting over power.

Offer your empire as a solution.

^^ I do, but the problem is, your line of thinking automatically assumes it's the only way to do things. That an interstellar empire NEVER can raise an army or have the ability to project force and that is MUST resort to flinging space rocks and building Death Lasers.

If the WMD option becomes so casual like that I highly doubt you're in a place worth living in. WMD options have been around for over 70 years in reality and not once have they been reduced to a casual thought. Even tactical use to knock out very local targets like a ship fleet, aircraft squadron or military facility.

And I know all the reasons you're gonna give me for why that is.

^ That's an easy easy way to get the people reunited in opposition to you. Especially if they figure out you were the one who started it.

Yeah that's why you do it Stargate Gou'ald style.

Toss big rocks at them, in such a way you won't be able to tell.

It becomes awfully suspicious that a meteor storm conveniently and precisely disposes of local government and military and then you show up offering an alternative to quell the chaos afterwards..

Tom: Glad to know your mind reader on top of everything else oh wait your not and you are still missing the point by a light year.

I never said it was the only way to do things again as per usual that is all Tom and no one else I also never said an empire couldn't raise an army again all you Tom. It's only mind reading if you do it on other people and not yourself.

The only WMD that doesn't have an extensive history including modern use in human warfare are nukes.

The situations nukes were considered for were significantly different then what we are talking about by leaps and bounds. You have gone beyond apples and oranges and sailed right into figs and kelp.

Nukes, as has been covered in several threads you have been in at this poin,t are not one trick ponies. You actually have to deliberately make a modern nuke dirtier then the efficiency of the weapon would otherwise cause. Both the US and Russia deliberately made their nukes dirtier then they had to be to induce longer lasting fallout and radiological after effects.

At the most efficient weapon yields made they are actually pretty clean leaving not a whole lot of contamination material behind. Of what material is left behind the vast majority of that material will decay away in a few short months at most. The long lasting materials are literally minute in total quantity and heavily reliant on deliberately making a nuke burst dirty to be even a moderate threat. Not only have we discussed this in the two sci-fi threads but even got addressed in the fallout threads pretty much for every game at least once. Using almost nothing but air bursts you would have almost no fallout at all and still have your massive destructive foot print.

Then you have diable yield nukes tech that has been around for decades which it doesn't take a lot to figure out why that is handy.

Then there are raidological weapons like Enhanced Radiation Weapons. Which can also be tailored for just how nasty and lingering they are depending on how you make and set, and use your bomb.

As for chemical weapons not only do they have an extensive history of use even into the modern era even most lethal ones break down in a few days at most. Again just like nukes you have to actually put effort into making them linger for notably longer periods. The most effective and dangerous agents break down in a few hours after deployment at most and even faster if there bright sunlight and wind. You can also create chemicals that are more debilitating then lethal.

Bio agents... guess what? That's right an extensive history of use and you have to deliberately make them in such way that they linger. There are quite a few different bio weapons that have been made from diseases that will burn themselves out with a fury in a few weeks leaving a trail of corpses to ones that have very low lethality rates but tend to take people out of action for a few weeks while they are very very ill. They even have some that only affect live stock and certain crops.

Given the fact all of that is possible with our own technology and we can actually clean up the vast majority of the remnants of WMD use fairly effectively, provided we don't do this on a global scale, that leaves only political taboos which all of them except nukes have been broken repeatedly. Now take that to the kind of tech that again permits a society that can possibly launch a massive planetary invasion across the stars. I am willing to bet they will have little trouble cleaning up after themselves unless they do something spectacular.

No Tom the chances of people uniting when their government vaporizes and their civil structure collapses over night is amazingly and depressingly low. We have a nice extensive amount of human history to draw on that shows pretty much every human society quite easily falls into chaos and infighting rather readily when a notable or key portion of the leadership suddenly dies. Hell human societies have had this problem with just one person dying.

The reason these weapons become an actually viable option is sheer amount of cost in man power, time, and pretty much everything else alone dictates you need a big stick to drive those down to make it worth while. Quite a few considerations have already been pointed out for you already and in past discussions.

No Tom you don't know the reason or what I am going to say because you tend to not even pay as much attention as you could and we have already thoroughly established you are in fact the worlds worst mind reader.

edited 4th Aug '16 6:06:02 AM by TuefelHundenIV

I was the one who suggested the destroy governments and offer relief thing.

Can we agree that the tactics one uses to subdue a planet will absolutely depend upon the long term strategic goals of the community which deployed the attacking force, as it always has? The type and amount of force they are willing to use will depend upon what they want to gain against the cost they are willing to bear. Strategy determines operations, and operations determines tactics. This won't change in the future.

edited 4th Aug '16 11:45:50 AM by DeMarquis

Echo: My bad so you did. It is a good idea to. Which is why the US and Russia went to such lengths with COG plans. Which of course were reliant on said government making it to the shelters in time. The actual nuclear war estimates of survival of said leadership to reach the bunkers is not very optimistic.

De Marquis; The overall point is such options become a reasonably viable option in the tool box for several reasons already listed. Unless you are taking a relatively soft target things are quite likely to get messy no matter what you do. Your options will ultimately include causing a shit ton of damage to urban areas.

Urban areas are surprisingly easy to rebuild. The heavy expense is the cost of occupation, esp if your goal is to control the local labor force.

Urban areas can be easy or they can be a massive pain in the ass. It really depends on what kind of damage you do to them and what you are replacing. If you do the kind of damage that guts infrastructure it becomes a significantly more involved and expensive process. It also takes longer to stand everything up again if you jack up infrastructure. That is especially true if you manage to bash the crap out of a cities infrastructure in any thorough fashion.

Generic housing is pretty easy to replace especially those small cookie cutter/cracker box homes. However larger buildings like sky scrapers, business centers, government buildings, and infrastructure facilities all tend to be a lot more expensive and time consuming to replace.

Historically, cities pretty much replace themselves. It takes a while, but if you're willing to wait ten or twenty years, people will rebuild what they need to get an urban center up and running again. What's expensive isnt rebuilding the cities, it's controlling them. If the population is resisting, even passively, the upkeep costs are very high. Administrative overhead alone will suck up most of the local surplus. And that's before you factor in losses to any active resistance forces. Most occupations dont pay for themselves.

Infrastructure isn't cheap especially properly functioning infrastructure. Like I said the residences are usually not the problem. It is everything that supports the city like government facilities and key infrastructure. Most residents don't have much ability to rebuild the infrastructure and usually need government help with that. Which is what happened in post war Tokyo and much like you said it took a few decades to rebuild the city but city government and others backed them up with the key infrastructure to support that rebuilding.

Sure, but the Japanese occupation was exceptionally low cost because the population was unusually cooperative.