challenge: invade the U.S

the magical sea lift from Europe

"In the late 19th Century, two steamers were considered to be required to transport a regiment of infantry on a long voyage. For a division of 10,000 men, a least 30 steamers were calculated to be required; for a corps of 33,000 men, 135 steamers. No nation except Great Britain and possibly France possessed enough ships to carry 50,000 troops across an ocean.

In theory, Great Britain might have transported 500,000 men; but that would have required all her shipping, which she could not have afforded because of her economic needs. An invasion of the United States by a European power was out of the question:

from "The American Way of War" Russell Weigley, 1973, page 168-169

who by the way is considered one of the greatest American military historians.

He is drawing from Reports to the Secretary of War, 1884, John Bigelow, Page 54-55, 1968 which is a compilation of reports made to that office over the period.

In other words, next time someone says the British can invade North America with a huge army point this out.

Note that shipping does include horses, artillery, bridging equipment, wagons, ammunition in quantity, forage etc

A typical steamer is about 3,000 tons in this era (as a high average), about double this size as of 1920, with liners of course being larger still (but they don't move cargo, only troops)

So in other words, if you need 135 steamers to move 33,000 troops, that works out to be 405,000 tons of shipping. That includes the 15,000 or so horses and mules, their wagons and artillery, and usually about 30 days worth of food for the men, far less for the mounts.

A horse typically eats about 4 times what a man eats (usually factored as 3 pounds a day for a man, about 5 when you count storage containers etc). In other words, 20 pounds per day per animal, or 200 tons per day for the corps. Horses can graze, but only when it is available, and European and Eastern North American horses are larger than Mustangs or other wild horses because they are raised on grain. Without grain they get sick and die pretty quickly

There is a reason the British didn't use a lot of cavalry or heavy artillery in their wars in North America. The logistics alone explain it.

Now of course you can ferry those troops over one corps at a time to friendly ports, which reduces your immediate lift requirements. But each corps is adding more and more logistical requirements which of course will require still more troops.

All of that is the main reason the US wasn't too concerned about being invaded during the 19th Century or later

Also consider what a heavy or light cavalry brigade would require, or for that matter a division or corps. You quickly begin to see how the American advantage of rail road capacity becomes very important. If nothing else, the Americans can move a vast amount of forage for their animals while the British have to haul most of theirs from Europe and then find a way to move it around Canada.

Later on, as armies acquire more motor vehicles, that massive requirement for fodder is reduced. HOWEVER, there is no oil production in Canada until late in the 20th Century, so every drop of gasoline and motor oil has to be brought across the Atlantic from tankers, which of course require tankers moving oil from the British sources of oil (Persia until later in the century) while the Germans would have to buy from Baku and Ploesti (assuming either of the nations involved are willing to sell). The Americans of course are awash in oil from California, Pennsylvania, Texas, Oklahoma and later on Louisiana. (being the largest exporter until after World War II)

The US Navy was one of the early pioneers of submarine warfare. It would be an expensive business for the invaders to get fuel across the Atlantic
 
Which the US naturally ignores. It doesn't notice the growing closeness of the UK, Germany and Mexico nor the growing hostility of the UK to itself. :rolleyes:

I once read that the average prelude to a shooting war during the Cold War as 11 months. Outside of that, while a string of events can be traced back after the fact, things just happen in the course of normal international events.

Either way, given the US only has 3 divisions in 1912 compared to over 100 for Germany and 24 for Britain even with a year's warning what will the US be able to do to stop the deployments of 50+ divisions to its borders in a period of a few months of a crisis?
 
I once read that the average prelude to a shooting war during the Cold War as 11 months. Outside of that, while a string of events can be traced back after the fact, things just happen in the course of normal international events.

Either way, given the US only has 3 divisions in 1912 compared to over 100 for Germany and 24 for Britain even with a year's warning what will the US be able to do to stop the deployments of 50+ divisions to its borders in a period of a few months of a crisis?


How does Germany and GB get fifty divisions on the US border in a few months? Black Magic? The US is three thousand miles away.
 
Moving enough troops and equipment like artillery, vehicles (or wagons/horses), food stocks, ammo, etc from Europe to Canada and/or Mexico will take time and effort that simply cannot be hidden. Once any war starts there will be issues with supply from Europe to North America, even if the USN is eventually squashed. I can't think of any reason this sort of buildup by the UK or Germany (Canada/Mexico) or even both can be seen as anything but preparatory to invading the USA. Even before that there will have been some serious diplomatic posturing so there will be lots of time for the USA to "mobilize", and remember that only a fraction of the "enemy" divisions will be available on the day of attack.

Unless you have a civil war/political collapse in the USA a successful invasion is pretty much ASB after 1900.
 
How does Germany and GB get fifty divisions on the US border in a few months? Black Magic? The US is three thousand miles away.

The same way Britain gathered a dozen divisions from garrisons around the world between the declaration of war and the formation of the 2nd Army in the BEF, by ship. As for Germany, they had a large fleet of ocean liners interned by the US in WW1, I assume these and a bunch of other ships could be pressed into service to conduct an administrative move over the period of a few months, these liners crossed the Atlantic in about a week.
 
Moving enough troops and equipment like artillery, vehicles (or wagons/horses), food stocks, ammo, etc from Europe to Canada and/or Mexico will take time and effort that simply cannot be hidden. Once any war starts there will be issues with supply from Europe to North America, even if the USN is eventually squashed. I can't think of any reason this sort of buildup by the UK or Germany (Canada/Mexico) or even both can be seen as anything but preparatory to invading the USA. Even before that there will have been some serious diplomatic posturing so there will be lots of time for the USA to "mobilize", and remember that only a fraction of the "enemy" divisions will be available on the day of attack.

Unless you have a civil war/political collapse in the USA a successful invasion is pretty much ASB after 1900.

What is the US going to mobilise, the 100,000 man Regular Army and the 112,000 man National Guard? This won't be enough to stop the sorts of forces an Anglo-German alliance would be able to put into the field within a few months of the start of the hypothetical crisis.
 
What is the US going to mobilise, the 100,000 man Regular Army and the 112,000 man National Guard? This won't be enough to stop the sorts of forces an Anglo-German alliance would be able to put into the field within a few months of the start of the hypothetical crisis.

in 1917-18, the US Army increased in size to a force of 2 million men in a year. While it would be short of artillery, rifles and practically everything else, some of those things can be purchased in a run up to war, and certainly with about 18 months (which is about when significant US production of aircraft, tanks, rifles, and artillery began in World War I) those problems can be solved. The US planned to have a 4 million man AEF in France by the beginning of the Spring of 1919, and would likely have done so if the war hadn't ended earlier.

It all depends on the run up to war and the perception of threat. Meanwhile the Navy is getting bigger and bigger in the period 1900- 1920, with a very significant fleet of dreadnoughts and super dreadnoughts being built which have the advantage of not having to sail all the way across the Atlantic to fight (or get repairs). The US Navy also built a lot of submarines and could easily build a lot more within a year. We know how effective submarines are. Considering it took the British until late 1917 to adopt convoys after losing a heavy toll of merchant ships (and only then after being pressured to do so), that trans Atlantic invaders are going to lose a lot of transports to US submarines once the shooting starts.

Also the British have exactly two major ports that lead to the Canadian hinterland, both of which can easily be mined on a routine basis, inflicting further losses. While the close blockade tactics are of the 19th Century will not work anymore against US ports and bases. It would be a difficult naval campaign in spite of the large numerical superiority the Anglo-German combined navies would have. The US East Coast is after all really long
 
The same way Britain gathered a dozen divisions from garrisons around the world between the declaration of war and the formation of the 2nd Army in the BEF, by ship. As for Germany, they had a large fleet of ocean liners interned by the US in WW1, I assume these and a bunch of other ships could be pressed into service to conduct an administrative move over the period of a few months, these liners crossed the Atlantic in about a week.

Germany did indeed have a large merchant marine and would add significantly to any trans Atlantic sea lift However, presumably everyone would notice when huge numbers of British and German cargo ships and ocean liners are no longer available.. There would be no surprise attack.

The more important issue is providing supply. In the 20th Century, generally speaking thousands of tons of supplies are needed on a routine basis for each corps of troops. This includes everything from fuel to food, ammunition to spare blankets. All of this has to funnel through two ports.. Halifax and Quebec (and Quebec is closed part of the year because of ice) and then be sent by rail to forward positions and logistics dumps.

In other words, a massive effort would be needed to expand Canadian railroad infrastructure to support this vast increase in traffic. That does take time, probably at least a year.

Otherwise, the Anglo-German invasion is not going to get very far into the US before they have outrun their supply infrastructure.

The Americans just have to fight a delaying action while they build their armies and enlarge their naval forces. The Navy would certainly use submarines and cruisers to hit the invaders sealift, while the battlefleet would make sure that any Anglo-German offensive efforts at ports was terribly expensive and risky. Eventually the Americans are going to have at least parity with the Anglo-Germans and then it comes down to will.

As the Anglo-Germans are the invaders, I suspect the defenders are going to have a bit more will to win. But that too is conjecture of course.
 
I understand what you're saying about mobilisation and agree that if the US has some time it will get ready with commendable speed. This is why I think that an invasion of the US heartland would require an absence of a prolonged rivalry with the US and Britain and Germany and be the result of some unexpected and sudden diplomatic flare up.

Such a scenario would play to the Anglo-German strengths of large military establishments and to the US weakness pre WW1 of a small army. The Anglo-Germans could mobilise their first line divisions and get them to North America long before the US could enlarge, train and equip their trained army from 212,000 to something that could match the A-G armies.
 
I understand what you're saying about mobilisation and agree that if the US has some time it will get ready with commendable speed. This is why I think that an invasion of the US heartland would require an absence of a prolonged rivalry with the US and Britain and Germany and be the result of some unexpected and sudden diplomatic flare up.

Such a scenario would play to the Anglo-German strengths of large military establishments and to the US weakness pre WW1 of a small army. The Anglo-Germans could mobilise their first line divisions and get them to North America long before the US could enlarge, train and equip their trained army from 212,000 to something that could match the A-G armies.

from what other people have been saying on here though, it would be a painfully slow process, funneling everything through two Canadian ports. The US has an advantage in that they don't have to send anyone overseas, and aren't so limited in logistics, having a pretty good railroad network. The AG might be able to get it done, concentrating a hell of a lot of their shipping and bludgeoning their way past the USN. They could get their men over pretty quickly, but assembling all the supplies is going to be time consuming. It sounds like it would be a close run thing...
 
C'mon you guys. OBVIOUSLY we're missing the true superpower with the capacity to invade the US.

The year is 2025. The economy is so poor, the President has to sell the Whitehouse, and live in a bungalow outside DC. Meanwhile, time-travellers have given Mexico Space-AK47s.

With a cry of '¡Viva el Imperio', the Mexican army pour across the border, to liberate rightful Mexican clay from its US occupiers.

;)
 
from what other people have been saying on here though, it would be a painfully slow process, funneling everything through two Canadian ports. The US has an advantage in that they don't have to send anyone overseas, and aren't so limited in logistics, having a pretty good railroad network. The AG might be able to get it done, concentrating a hell of a lot of their shipping and bludgeoning their way past the USN. They could get their men over pretty quickly, but assembling all the supplies is going to be time consuming. It sounds like it would be a close run thing...

Perhaps the Pacific could get greater use, IOTL a couple of Indian divisions got to France in October IITL they could cross the Pacific and use the CPR to get to their start line.

I'd also envisage that while the US heartland is the target the AG with a bit of Mexican help would launch offensives from the south both to capture territory in Texas and California and to tie down the tiny US Army.
 
The French and Russians would need to be part of this alliance too, or at least firmly neutral. Because if they are not, the US will offer France Russia everything imaginable and then suddenly those German troops are staying in Germany.

Let's say France, Mexico, and Spain are part of the coalition and Cuba is still Spanish. Use Cuba, Bermuda, Canada, and Bahamas to blockade the US. The Royal Navy and HSF controls the Atlantic while building up forces in the Caribbean and Canada for an eventual invasion.
 
The Queen Elizabeth and Queen Mary could carry about 15,000 troops each across the Atlantic - smaller liners 5,000+ each. However this is just the troops and their personal weapons, minimal other supplies. Realistically speaking given transit times and loading/unloading all those troops and whatever small amount of supplies that come with them you get two round trips a month from Britain to Canada. For converted liners going to Mexico from the UK maybe 1 1/2 round trips a month, for ships sailing from Germany the number of round trips is even less. For the freighters that would carry the bulk of the supplies not even one round trip a month. This is without convoys during peacetime, and you will need LOTS of freighters and you'll be severely limited by the capacity of the Canadian and Mexican ports, and difficulties with rail capacity in Canada and a horror show with rail capacity in Mexico.

Once any fighting starts, the Anglo-Germans are going to have a huge problem with antisubmarine warfare. Depending on when in the 20th century this happens simply being able to have escorts to go the distance to Canada/Mexico will be a problem. The US has great choke points to lurk at for anything going to Mexico, and knows where everything has to go for Canada - only 2 ports period. Again, depending on when this happens Canada has, at best, a limited ability to provide supplies locally other than food/fodder, and Mexico way less. OTL while LL supplied a great deal to the UK and US forces brought most of their own gear, when the Allies invaded France a substantial amount of the "stuff" was manufactured in the UK - not so in this case.

While the USA does not have as much space to trade for time as the USSR did, the USA in the first half of the 20th century has a decent road net (way better than the USSR in 1941), a very dense rail network, and a well developed internal waterways system. All of this works in favor of the defender. If you posit that the A-G alliance has been operative for some time and has been gradually building up in Canada, then the USA will have reacted by building its military, border fortifications, and so forth. Even the most "isolationist" USA will respond to this sort of hostile military build up .

Assuming you go from peaceful relations to war, this process will be no less than a year and realistically 18-24 months before this A-G alliance can have adequate forces and supplies in the western hemisphere. There is no political party or leaders in US history who would sit there and do nothing in response to this. It would be hard for this alliance to get a 2:1 or 3:1 force on the ground before the USA had become pretty impregnable - sure coastal raids, air raids, some local advances possible even probable, but without two or three to one on the ground its not happening.
 
Britain remains neutral during World War I and does not apply it's navy to stop German shipments across the Atlantic at the time. Americans still consider joining the war effort on the side of the Allies France and Russia.

Mexico decides to take up Germany on it's offer to invade the southwestern United States during or after the war and reclaim Arizona, New Mexico, and Texas. This takes place in 1917 as a distraction from Americans being able to send forces to Europe instead.
 
Personally I think people are being very pessimistic about how long it takes to move a corps of troops across an ocean. It didn't take long for the Indian Corps to reach France in 1914, a couple of months, nor did it take long to gather up all the British regular army garrisons around the world and concentrate them into divisions for the western front. What's more in April 1915, 8 months after war had broken out the British had assembled 4 divisions to invade Gallipoli as well as growing the BEF, conducting operations in Iraq and in Africa. Personally I don't find it a difficult stretch of the imagination to change the destination of these deployments to various points in Canada and Mexico.

As for the Germans they don't have an example of global deployment, but given how well they moved their armies around Europe in WW1 I wouldn't think the problems would be insurmountable.

In fact the only insurmountable problem I foresee is how the US is going to deal with multiple divisions coming from at least 4 points excluding any amphibious landings with 100,000 regulars and 112,000 national guardsmen. Where are the training cadres going to come from to expand the Army if these troops are engaged on multiple fronts?
 
Personally I think people are being very pessimistic about how long it takes to move a corps of troops across an ocean. It didn't take long for the Indian Corps to reach France in 1914, a couple of months, nor did it take long to gather up all the British regular army garrisons around the world and concentrate them into divisions for the western front. What's more in April 1915, 8 months after war had broken out the British had assembled 4 divisions to invade Gallipoli as well as growing the BEF, conducting operations in Iraq and in Africa. Personally I don't find it a difficult stretch of the imagination to change the destination of these deployments to various points in Canada and Mexico.

As for the Germans they don't have an example of global deployment, but given how well they moved their armies around Europe in WW1 I wouldn't think the problems would be insurmountable.

In fact the only insurmountable problem I foresee is how the US is going to deal with multiple divisions coming from at least 4 points excluding any amphibious landings with 100,000 regulars and 112,000 national guardsmen. Where are the training cadres going to come from to expand the Army if these troops are engaged on multiple fronts?

you still have solved the logistics issues raised... and they are indeed very large
 
you still have solved the logistics issues raised... and they are indeed very large

What are these great logistical issues when facing an army of 212,000 men spread across an entire continent? The A-G armies would be advancing into some of the richest country in the world that is virtually undefended. If the Germany armies can live off the land during the advance in Belgium then it can be done in Wisconsin, Michigan and New York state.
 
Are people forgetting that Canada is a positive producer when it comes to food? so you won't need to ship all the food over maybe some but not all.

and if Mexico is being added there is another semi decent food source.
 
Are people forgetting that Canada is a positive producer when it comes to food? so you won't need to ship all the food over maybe some but not all.

and if Mexico is being added there is another semi decent food source.
The Prairies are incredibly vulnerable in a war with the US, the food production and distribution there would be susceptible to disruption.
 
Top