Minimum Number of Troops needed for Planetary Invasion

[Morningstar]

How many soldiers normal sentient's/clones/droids would you need to conquer and hold a planet? Taking into consideration the type of planet as well, for instance the number needed for Coruscant would be different to the number needed for Naboo.

[Srelex]

This depends on the level of orbital support.

[Ghost Rider]

Impossible to note because the variables are orbital or any of such one shot nonsense. You have to have an idea of what your objective is, long term projections and finally what can your army devote to this effort. As such, this question is absolutely useless since it is incredibly broad with no possible definitive answer.

[Morningstar]

Lets say they have secured the orbit but are unable to fire onto the surface due to political reasons or a desire to keep the planets industry intact.

[Temujin]

Its not that simple. Military planning requires a significant amount of intelligence to be collected and processed in order to develop any kind of effective plan for an operation. And numerous variables have to be taken into account if its to have any hope of success.

For example, for starters you need to take into account the following:

• - Planet type: Gravity, terrain, climate, etc.
  - Population levels and density
  - Composition of the population in terms of species, cultures, factions, etc.
  - The level of militarization and the type and number of defenses on the planet
  - etc.

Each of these needs to be meticulously broken down and analyzed against know information in order to develop a projection of how many troops you will need to successfully invade, and then successfully hold onto the planet; as well as how many casualties you're likely to sustain.

Edit: And even this is overly simplistic. Find a book on military planning at your library if you really want to go down the rabbit hole.

[Mr Bean]

Lets say they have secured the orbit but are unable to fire onto the surface due to political reasons or a desire to keep the planets industry intact.

30 to 1
One soldier for every thirty civilians. You just asking us to pacify Germany on a planetary scale and one soldier for every thirty civilians is the ratio to both pacify and make sure your able to conduct counter insurgency if needed. You might be able to par that down to 50 to 1 via heavy use of robots but you still need in that circumstance. Thirty to one, got 30 million civilians? Best have a million soldiers to make sure you can be everywhere you need to be.

You can get by with less if the population is not actively fighting you but then your still at best at 300 to 1. Holding planetary populations when you can't simply threaten to drop rocks on their heads if they don't stay in line means you need to have a pretty large ratio of soldiers to civilians.

[Morningstar]

Makes sense thanks

[Azron_Stoma]

If memory serves during World War 2 there were around 100,000,000 servicemen worldwide, with the overall global population of the time being on the order of 2.5 - 3 billion. so Mr Bean's assessment sounds about right.

[Littlefoot]

That is to hold. Assaulting a city you want at least 3:1 in your favor, especially if you cant use heavy bombardment. Since your army has control of orbit, and I assume the air, most of the fighting will be in cities. But once the fighting is done, then you can go to occupation ratios, which will be either less then the 30:1 or more effectively utilized due to not having supply lines to protect.

[Mr Bean]

That is to hold. Assaulting a city you want at least 3:1 in your favor, especially if you cant use heavy bombardment. Since your army has control of orbit, and I assume the air, most of the fighting will be in cities. But once the fighting is done, then you can go to occupation ratios, which will be either less then the 30:1 or more effectively utilized due to not having supply lines to protect.

Unless you have transporters your going to have to have orbital supply depots or ground based supply depots and the shuttles that run between space and your army's camps. There's still going to be some kind of logistics unless you can beam food & ammo directly into the troops backpacks. Because the instant you make the planet provide supplies your dependent on their logistics which again without transporters will be based on the pathways of some sort. Sure your future delivery truck might fly at mach 10, but it still needs to land somewhere and take off from somewhere. Both of which can be attacked.

[Sea Skimmer]

Unless you have transporters your going to have to have orbital supply depots or ground based supply depots and the shuttles that run between space and your army's camps. There's still going to be some kind of logistics unless you can beam food & ammo directly into the troops backpacks. Because the instant you make the planet provide supplies your dependent on their logistics which again without transporters will be based on the pathways of some sort. Sure your future delivery truck might fly at mach 10, but it still needs to land somewhere and take off from somewhere. Both of which can be attacked.

It'd be pretty easy to shove supplies into an expendable reentry vehicle which would guide on the way down, apply air breaks or retrorockets in the lower atmosphere and then have parachute or repulsorlift down to a precision landing given Star Wars technology. We could do it today if we felt like spending the money, similar concepts have been proposed.

A big Trade Federation style transport ship could bring millions of RVs like this along, allowing specific platoons and vehicles to get several thousand pounds supply drops on demand for weeks on end, even if you had a number of whole armies to supply. Droids would pack the supplies into the RVs based on reports from the ground pounders. Hell they might have fully automated logistics reporting, Stormtrooper armor could well be advanced enough that it can keep track of each time the user reloads or uses a grenade. In real life we already have vehicles that can tell the user what repair part is needed, it'd be easy to scale that up to radioing the order to orbit. So supplying an assault landing force should not be a very big deal if you have anything like decent planning. Reusable supply transports would only come into play once you had nice big secure landing zones, and enough space to land and operate supply vehicles to haul stuff from the landing zone to the forward forces.

As for 'heavy bombardment' I dunno why people think firepower from space has to be heavy. Nothing stops you from deploying weapons no more powerful then an artillery shell or a 500lb bomb from space. Star Wars tech would make it be within reason to drop cans of tear gas on a riot from space. So a ground force might never be allowed to call on heavy firepower, but it could still really really fuck an enemy up calling down thousands of Space Hellfires on specific targets.

[Mr Bean]

I'm not saying there's not solutions but even in a hypothetical space supply bomb (WWII, need to get supplies to someone? Pack the whole thing into a bomb case which deploys a parachute or is simply well padded so your bombers can drop supply bombs over friendly troops. A space based version of that can be made sure enough but you risk the same thing the plane based version does, such supplies being intercepted and redirected.

Again I'm assuming a hostile local population. Nine out of ten headaches can be solved by having a friendly local population.

[Shroom Man 777]

If sufficiently precise, ground forces can even call on orbital counter-sniper fire to headshot some Rebel scum with a sniper blaster! Or to orbitally fire a stun ray at some captive who's escaped! Or shoot the weapons off the enemy's hands, if they're to be captured alive.

[Thanas]

Lets say they have secured the orbit but are unable to fire onto the surface due to political reasons or a desire to keep the planets industry intact.

30 to 1
One soldier for every thirty civilians. You just asking us to pacify Germany on a planetary scale and one soldier for every thirty civilians is the ratio to both pacify and make sure your able to conduct counter insurgency if needed. You might be able to par that down to 50 to 1 via heavy use of robots but you still need in that circumstance. Thirty to one, got 30 million civilians? Best have a million soldiers to make sure you can be everywhere you need to be.

You can get by with less if the population is not actively fighting you but then your still at best at 300 to 1. Holding planetary populations when you can't simply threaten to drop rocks on their heads if they don't stay in line means you need to have a pretty large ratio of soldiers to civilians.

I would up that. Germany was a wholly defeated nation with no spirit of fighting whatsoever left in them. Also, Germans obey the law and order more than other nations.

So you might need a higher ratio than 30 to 1.

[Illuminatus Primus]

It'd be pretty easy to shove supplies into an expendable reentry vehicle which would guide on the way down, apply air breaks or retrorockets in the lower atmosphere and then have parachute or repulsorlift down to a precision landing given Star Wars technology. We could do it today if we felt like spending the money, similar concepts have been proposed.

If the re-supply drops are excessively cheap/fragile, you might run into problems of pretty much ubiquitous multi-purpose LOS weaponry which could be used for anti-RV purposes, and then one enters a question of economy versus the defense deploying adequate vs. sufficiently cheap ARV weaponry to deny logistical support, while the enemy can invest in counter-battery support and hardened/active-defense RVs (but then is it worth to have them be cheap disposables?).

Of course the Gungans make pretty arbitrarily small local defense shields seem practical, and we've seen everything from field unit sized umbrella shields, base-to-city sized shields, theater, continental and finally global and ground-based satellite shielding.

[Aaron]

That is to hold. Assaulting a city you want at least 3:1 in your favor, especially if you cant use heavy bombardment. Since your army has control of orbit, and I assume the air, most of the fighting will be in cities. But once the fighting is done, then you can go to occupation ratios, which will be either less then the 30:1 or more effectively utilized due to not having supply lines to protect.

7:1 is actually the current preference for FIBUA, 3:1 is the standard for assaults in general.

[recon20011]

That is to hold. Assaulting a city you want at least 3:1 in your favor, especially if you cant use heavy bombardment. Since your army has control of orbit, and I assume the air, most of the fighting will be in cities. But once the fighting is done, then you can go to occupation ratios, which will be either less then the 30:1 or more effectively utilized due to not having supply lines to protect.

7:1 is actually the current preference for FIBUA, 3:1 is the standard for assaults in general.

I was actually going to ask that. My understanding has always been 3:1 is the absolute minimum but even then you're crazy to try it. And just to clarify, thats 7:1 attacking soldiers versus defending soldiers, not versus civilians, right? Because for occupation duties its a soldier:civilian ratio.

My question would be: What is the purpose of the occupation? To gain control of the manufacturing centers? It appears that way since you want infrastructure left intact. How long do you want to control it for? Forever? Or just a couple years? Because if its "forever" then you want to give the locals a reason to like you. Which probably means more troops in the initial assault, especially military police, so your army can swiftly take over the role of local government until an occupation government is established.

[Azron_Stoma]

It'd be pretty easy to shove supplies into an expendable reentry vehicle which would guide on the way down, apply air breaks or retrorockets in the lower atmosphere and then have parachute or repulsorlift down to a precision landing given Star Wars technology. We could do it today if we felt like spending the money, similar concepts have been proposed.

If the re-supply drops are excessively cheap/fragile, you might run into problems of pretty much ubiquitous multi-purpose LOS weaponry which could be used for anti-RV purposes, and then one enters a question of economy versus the defense deploying adequate vs. sufficiently cheap ARV weaponry to deny logistical support, while the enemy can invest in counter-battery support and hardened/active-defense RVs (but then is it worth to have them be cheap disposables?).

How tough are Predator I Probe-Mate jump pods?
could always replace the hyperdrive with a shield generator and the probe droid in it with some of the supplies needed, those things hit the ground pretty hard though, which depending on the landing zone may or may not be a good thing, especially if you have allot of them.

[Aaron]

I was actually going to ask that. My understanding has always been 3:1 is the absolute minimum but even then you're crazy to try it. And just to clarify, thats 7:1 attacking soldiers versus defending soldiers, not versus civilians, right? Because for occupation duties its a soldier:civilian ratio.

Yes, 7 of your soldiers for every 1 of their soldiers.

[recon20011]

I was actually going to ask that. My understanding has always been 3:1 is the absolute minimum but even then you're crazy to try it. And just to clarify, thats 7:1 attacking soldiers versus defending soldiers, not versus civilians, right? Because for occupation duties its a soldier:civilian ratio.

Yes, 7 of your soldiers for every 1 of their soldiers.

Thanks! Just wanted to make sure I was thinking along the same lines.

For resupply why go through the expense of one-time-use drop pods? Just use whatever you would normally use during a military operation for resupply. During the First World War they had tanks specifically designed to carry supplies to the infantry during attacks. Your army should have something similar to resupply front-line units.

My opinion for an assault though, capture spaceports and major manufacturing centers first along with a main landing zone which you will develop as a major staging area. Force your opponents to attack YOU in THEIR cities. They aren't going to like it. Try to minimize civilian casualties and make sure that basic civilian infrastructure is kept intact in the areas you occupy. Then the civilians will look at what they're own government is doing as it attacks your defenses: they will most likely be destroying the civilian infrastructure. Then you get a good PR team together and have them spin everything your way as best you can.

[Grif]

I was actually going to ask that. My understanding has always been 3:1 is the absolute minimum but even then you're crazy to try it. And just to clarify, thats 7:1 attacking soldiers versus defending soldiers, not versus civilians, right? Because for occupation duties its a soldier:civilian ratio.

Yes, 7 of your soldiers for every 1 of their soldiers.

Thanks! Just wanted to make sure I was thinking along the same lines.

For resupply why go through the expense of one-time-use drop pods? Just use whatever you would normally use during a military operation for resupply. During the First World War they had tanks specifically designed to carry supplies to the infantry during attacks. Your army should have something similar to resupply front-line units.

My opinion for an assault though, capture spaceports and major manufacturing centers first along with a main landing zone which you will develop as a major staging area. Force your opponents to attack YOU in THEIR cities. They aren't going to like it. Try to minimize civilian casualties and make sure that basic civilian infrastructure is kept intact in the areas you occupy. Then the civilians will look at what they're own government is doing as it attacks your defenses: they will most likely be destroying the civilian infrastructure. Then you get a good PR team together and have them spin everything your way as best you can.

This is assuming the civilian population is sympathetic to your cause to begin with. Or at least are ambivalent towards their government. If you get a fanatical population whose undying loyalty to the <insert governor here> is the norm, then you'll probably just end up with guerrilla uprising in the cities. Same thing happens if your army happens to be the Big Bad of the Galaxy and the good people of Planet X aren't too keen to be conquered by the local baddies.

[Knife]

Plus those in the defense always have the advantage and need less people to exploit it. Sure, attackers get to pick the time of engagement, but defenders get to bonus of covering the avenues of approach which takes less people to cover those area's. They also get the advantage of preparing the defense and putting together defense in depth for the attackers to have to over come further acting as a force multiplier. It gets to the point where ever defender is worth 10 attackers.

[Night_stalker]

I would have to say that it depends on the size of the planet, the morale of the population, the terrain, the troops that can be used, and numerous other factors, as per Ghost Rider.

[Crazedwraith]

It was indeed Lorth Needa as a Lt. Commander in charge of a Carrack Cruiser.

[Lord Relvenous]

It was indeed Lorth Needa as a Lt. Commander in charge of a Carrack Cruiser.

What? I don't get how that relates to the discussion at all.