Let’s say I have an island, similar to the likes of Kerguel in the Indian Ocean, as the island is hundreds of miles away from any mainland, has no immediate resources, a tiny population and no strategic value; But for one reason or another, the government that has this island as a colony has decided to dramatically increase the military personal at this middle-of-nowhere island. Some civilians also decided to travel and work and live (at least for a while) on this island. Why would the island be a hive of activity if there is no value strategically, politically, or in terms of resources?
The island may not have strategic value per se, but it may make sense politically that it holds that island. US and UK made an airlift into Berlin while it would not be warranted by the city itself. Spain sent a commando attack force to recover a rock pastured by goats. Just an interest by another country on that island would make the government to send a message visibly reinforcing their presence there.
Not to mention all the other reasons an isolated island could attract a lot of population:
- A political or religious leader could be visiting the island "soon" (which might be next year)
- A recent translation of a Mayan prophecy designates this island as the place from which aliens will come to visit Earth / take human race to their world.
- A popular reality TV program is filming on that isolated location, which brings in a lot of people (cast members, production crew), and could cause more military personnel (for example, since they are so isolated the island traditionally had the army perform the duties of a police force)
No inherent Strategic Value ...
The requirement for "no strategic value" kills many explanations which might otherwise apply. It cannot be a waystation to somewhere else, or it would be strategic. It cannot be far enough from prying eyes to hide an ongoing secret program, or it would be strategic. It cannot justify claims to an exclusive economic zone, or it would be strategic.
Would it be possible to make it merely indirectly strategic?
- Something happened there in the past and independent investigation would be embarrassing. Like Anthrax tests. Or some old missile system was dug into the rocks and obliterating the traces would itself leave traces.
- It is a strategic interest to support a certain interpretation of international law, and holding on to the island showcases this interpretation as it applies elsewhere.
- It is a suitable training site simply because it has little inherent value. Real estate is cheap and flight restrictions don't annoy the economy.
Top-secret Resources and/or Strategy Importance
Government officials have discovered that there is an attack plan that a presence on this island would foil, or that scientists have discovered a way to use some insignificant material found on this island in important ways.
Safe Location for Research
The low population, distance from other locations, difficulties getting on and off without being noticed, and little interest to outsiders combine to make it an ideal location for research. Not only is it safer because there are fewer people that could be injured, it makes espionage more difficult.
Its very obscurity will ensure all this draws attention. It is vital that attention not be paid somewhere else, and this will at the very least draw down the resources that could be used for that.
And you might roll up a few of their assets, too.
A defeated charismatic dictator has been exiled to the island, as happened with Napoleon, first on Elba and then on St Helena. This obviously necessitates a substantial military presence to prevent him from being liberated by his remaining followers (as also happened with Napoleon on Elba).
As a waystation. The ocean is big, and ships can be out to sea for a long time, which is not easy or fun for the ships or their crews. The more friendly ports you have to resupply from, the less space your ships will have to devote to supplies and the more room they have for combat- or other duty-related equipment.
Now ideally you'd want your waystations to be ports in their own right: it's cheaper, and you can turn a tidy profit off the merchant traffic, but for that reason, valuable ports are often snapped up by rival empires. You might have to make do with building your own waystation, but it's better than nothing.
When you say no value/resources, I am taking that to mean none at all, not just "none apparent," as secret reveals solves all mysteries.
One mundane, frustrating, and all-to-common reason? Politics. General A needs to increase his deployment numbers to get more funding . . . Hey let's build a base! That of course attracts civilian support, etc.
edit: Since the OP gave the condition of no value to the island, the value must come from something else. In this case, the value is in the process, not the result. Military build up on this particular island is of no value. However, military build-up in-and-of-itself is a lengthy, expensive, labor-intensive process that can provide value and benefit to a great number of interested players. Contractors, unions, vote-seekers, power brokers . . . there are unlimited ways to game this system, with the benefit that no body bags will come home to bring attention to this decision.
Conversely, these things can all be done out of spite, or even treachery! Suppose a general is really a foreign agent. Directing resources in this way depletes a nation's ability to respond to actual threats.
Consider the island of Kolbeinsey off the northern coast of Iceland. Ostensibly, it is a barren rock with no resources or strategic value. However, what it does do is extend the territorial waters claimed by Iceland due to the 12-mile radius around the island marking the border to international waters. Due to sea-level rise, it is slowly disappearing, currently only existing above water at low tide.
Now there may not be much point of trying to put a military contingent on this particular tiny piece of rock (indeed, they'd have to be good swimmers since it's underwater half of the time), but you could imagine a similar case of an island owned by a country which does nothing but extend their territorial claim over the surrounding waters.
Sometime the strategic importance is hard to assess, here is a simple example:
An island lost in a sea far away from any country.
Well, often these are extremely interesting because they can for example act as a SIGINT (Signal Intelligence) collection point:
The owning country can install antennas and processing stations that will listen to the radio spectrum, either from other parts of earth or from satellites, and collect them to get either clear text messages (decreasing probability), have raw material for hostile cryptanalysis, or perform traffic analysis (deduct goals and movements from mere traffic presences, sources, etc...) etc...
These locations can also serve as fiber optics interception stations, retransmitter station locations, etc...
So actually something seemingly of no value is of great importance: it stays under the radar.
PS: many personnel from intelligence agencies running these stations are actually civilians working for these defense agencies.
What would cause a heavy military or civil presence on an island with no strategic value?
That is quite close to the definition of a paradox. And the source of the paradox comes from the undefined "strategic". It itself, the word is "big", but means nothing. To make it significant, it had to be paired with other clarifying words. E.g.:
- strategic military position;
- source of strategic resources (e.g. the last adamantium mining place);
- strategic location for secret testing of something;
- strategic place for performing some activity (e.g. some sports);
Now of course, one thing can be irrelevant one day and become strategic during the next day. Why ? Because something has changed.
This is exactly what you want to exploit. The island had no strategic importance. But now it has strategic importance because something changed. What changed? Choose anything that fits your needs.
E.g.: the ocean floor was noticed to raise in the area, and the small significant island will become the launching pad for interstellar missions. The current size is not suitable to hold the required infrastructure for launching the missions, but in 10 years enough land will be available to start building. Of course such an asset must be protected by the military, and civilians were brought to provide services; some of the civilians are the families of the military people.
Another e.g.: the island was actually found to be the sediments covering the lost city of Brth'am-tek (please feel free to invent any other name). The military provides protection, the civilians do archeology.
Your country says this is your island. Another country says it's their island. Who's the winner? Flooding the island with your civilians and military alike makes it hard for the enemy to claim it as theirs.
Real-life example (sort of): Machias Seal Island, the last disputed territory between Canada and the United States, 20km from the mainland. The Canadian Coast Guard has automated all lighthouses, except the one on Machias Seal Island, for which it employs two lighthouse keepers.
Your economy would collapse if you stopped expanding.
If you're building a city there: You're a former superpower thats transitioned to a service economy that is trying to achieve greatness again by basically doing each others laundry. The only thing keeping your economy afloat is construction and expansion for your growing population. Expanding onto a remote island is one way to keep the ponzi scheme going long enough to get you to the next election.
If you're builing a military base there: your economy is in shambles and the only thing keeping it afloat is your massive military spending into the military industrial complex. Unfortunately you can only put gold plated F-35s in so many places on an airbase before the base is full. So you start putting airbases all over the planet on any rock you have a claim to, so you can avoid cutting those military contracts that are keeping the bulk of your population employed.
In 1947, the Royal Navy decided to detonate 6700 tons of explosives on the island of Helgoland, creating one of the biggest non-nuclear explosions in history (undoubtedly with significant military presence and efforts before the detonation).
From today's viewpoint, the island was of relatively minor strategic value, with no significant number of inhabitants - You could assume they did it simply "because they could" (or, maybe, as a simple way to get rid of surplus WW II bombing arsenal - but that's just an assumption).
Conclusion: You don't need a reason, at least not a very good one. Reality is sometimes surprisingly unreasonable.
As a diversion.
We actually planned all that originally for another place, which has a large, non-obvious, super-secret strategic advantage.
Then it partially leaked. A rival got to know that we were about to put a heavy presence in a place with a large, non-obvious, super-secret strategic advantage.
We know that they know, but they probably don't know that we know that they know.
What to do? Why, replan the heavy presence to the middle of nowhere. If we manage to pull it off, it will send them in a wild goose chase. After a couple years, we'll put a smaller base in the real strategic location on a carefully manufactured pretext.
...or as a cover
Alternatively, our real secrete base is actually very near to our publicly known useless one. We can't just send a bunch of ships to the middle of nowhere and not have anyone notice, but we can send a bunch of ships to the middle of nowhere, and then have one of our many useless coastal patrol vessels routinely supply the real base just down the way.
Have a look at the Thirty Six Stratagems
The thing about "no strategic value" is how malleable 'strategic value' is; putting lots of people and materiel into a place makes it a strategically valuable position. The Thirty Six Stratagems are an early Chinese treatise on, well, the art of war (but not Sun Tsu's famous essay). Several could easily explain the scenario you describe:
- Wait at leisure while the enemy labors
- Make a sound in the east, then strike in the west
- Openly repair the gallery roads, but sneak through the passage of Chencang
- Lure the tiger off its mountain lair
- Disturb the water and catch a fish
- Feign madness but keep your balance
- Decorate the tree with false blossoms
Never underestimate the power of bullshift. People like to say Money talks, bullshift walks; this is just another lie bullshift uses to make people underestimate it.
What about cultural significance?
Maybe this island has no strategic value or resources, but something cultural happened (or is believed to have happened) there. Perhaps an event of great religious significance took place on this island? Maybe a cultural folk hero was born there? This could make the island a destination of pilgrimage, and also a psychological target for enemies of the ruling nation. The nation in possession of the island defends it because it is seen as a symbol of who they are as a people.
It isn't a perfect example, but consider the Statue of Liberty. It doesn't actually do anything of strategic value, but it is a national icon. Looking back to the years after 9/11, it was guarded quite heavily. The nation felt it must be protected because of the idea it represented.
Perhaps the military stuffed up, spelled a name wrong or wrote coordinates down wrong.
I think that if that people arrived at the correct island intentionally that makes the island strategically valuable, as it was by intent. Correspondingly, choosing the island because it has no intrinsic value makes it, contradictingly, valuable.
If you felt like being pedantic, the act of arriving there probably makes the island valuable in some sense. Though you could argue that the island had no/little value prior to arrival.
The Island will become strategic only if a truly strategic alternate island is captured or embargoed. It is part of a backup plan. By building a base there, you absorb a portion of the strategic value of the other location, so that losing either location is less damaging to your position.
You deny an enemy a strategic location from which to attack you. It is valuable to them, not you.
Most of them are not actually military personnel. They are not persons at all.
They are something else. Real military personnel in boats patrol the water and ward off anyone interested. Satellite images show the structures and vehicles and people walking around in uniform.
If you were sent onto this island and used your skills to get close you would notice that these people in uniform are unusual. Their uniforms do not fit right. They gather in groups but they do not make any sounds. Their movements are disturbing to watch. They are not people. They are something else.
Clearly the government that owns this island has disguised them as military personnel because an accumulation of such has plausible reasons that the government might reasonably decline to explain. What exactly they are is an open question and one you should answer unobtrusively and, you wish now, from a greater distance.
You mentioned civil presence. Gather hobbyists, gawkers, and astronomers for a...
Total solar eclipse
... or any other kind of astronomical or atmospheric event really. It needs to be rare enough to warrant the travel, spectacular enough to be cool, and happen to be best observable from this particular island.
The maps of total eclipses can get pretty complicated, hence the strange location of the island might be explained. Another variant (for an island in the polar north or south) is aurora borealis, which should apparently be most spectacular exactly there. Some other kind of an astronomic event, such as meteor shower (should be world-wide, a particular large meteor with a predicted impact location? But not too large to not burn up completely, of course!), re-entry of a larger satellite, re-entry (to water, hence mostly US tech) of a space fare, solar panel flares of a larger satellite / space station.
For instance, the island used to be a bustling center for trade due to its location. Control of which would grant power/money/etc. In battling for control of this island hundreds of thousands of soldiers have died over the course of centuries. Those are honoured by numerous monuments spread out over the island. All of which are guarded by a large armed force as a sign of respect to the fallen.
Due to erosion/climate change the island has slunk down significantly. Trade is no longer possible and the only remaining people on the island are the soldiers protecting and maintaining the monuments. Keeping these soldiers there might be political, but could very much also just be a feeling of what is "right".
To gain access to resources and to gain sovereignty over the sea.
If you own an island (ok, you may not own it really, but you placed fortresses and troops there so who's arguing?) you own any resources under the sea (oil! minerals) and the fish in the sea around it.
You can also make like a pirate and interfere with passing ships.
This is not fantasy; a large ambitious Asian country is - umm - acquiring islands, atolls, and even tidal reefs in the South Pacific right now.
Edit: You could say an island suitable for acquiring in this way must be by definition strategic. But if it's not strategic till somebody occupies it?
The Island is a relay
Well, even if this is far from everything and have nothing on this may have a strategic value. Nowadays there is satellite to almost everything but if people wanted to exchange in long distance with no satellite having a relay here may be a good option. That may mean something is gonna kill the satellite and there is preparation to be ready.
Or for a less catastrophic model this is far from lands SO in the middle on ocean. Satellite is good but far if you try to discover deep water. A station that can relay (yeah that's the point) communication or handle data without having to navigate or a little bit is interesting. There is no need to consider the travel on the energy calculation.