<snip>The US Navy post 1912 is the 3rd largest in the World, and post 1918 is the largest or second largest depending on which year you look at. That matters a lot too.
ITTL, you have no Washington Naval Treaty with Anglo-American hostility. That leaves the Royal Navy with a vast force of pre-dreadnoughts, worn out dreadnoughts (due to long term wartime steaming), and post-Jutland obsolete dreadnoughts. Granted, the USN's dreadnoughts will also be post-Jutland obsolete, but their BB force will be far fresher.
The British will only have the QEs as first class super-dreadnoughts, while they are faced with a post-WWI naval arms race that they can't possibly afford. Even Japan is well placed to catch up with the RN if this continues, and Japan really isn't in a position to do much against the US beyond the Western Pacific without aircraft carriers.
But why? You don't need to project an army into Des Moins, Iowa to force an American surrender.
I think you meant to say "Sues for peace/pleas for an armistice".

A "surrender" is ASB.
Really pre-WW2 all you need to do is occupy chunks of the east coast.
The one area that the penny-pinching US Congress never stinted on regarding military spending was the US Coastal Artillery Corps. Every year Congress would issue a level of largesse upon coastal defense that was far greater than the army ever wanted, asked for, or needed. This was due to the idea of coastal defense playing into the natural Isolationist tendencies of the United States pre-Pearl Harbor plus the opportunity of House and Senate members feasting on federal spending directed at US coastal constituencies ($$$ for construction contractors and jobs).
The US had the largest most developed coastal defense system in the world all the way up to VJ-Day, when Congress could finally bring itself to turning off the spigot. One reason why Bataan held off the Japanese for as long as they did was due to the big guns on Corregidor (sp?

). The day after the last gun on that island fortress was silenced (due to lack of spare parts) was the day the garrison surrendered.
The role coastal artillery would have to play in any ATL invasion of the USA is largely overlooked; outside of the Philippines and Fort Sumter the USCAC (AFAIK) never had a chance to fire its guns in anger in its history.
Taking the East Coast of the USA with the forces available to hostile powers in the 20th century is not ASB, but it IS Unspeakable Seamammal.
If the question is could any power or even reasonable coalition in the 20th century project an army across the ocean, supply it and then march it across the entire continental United States and occupy the whole country then the answer is a resounding NO, even all the major powers of Europe combined couldn't do that, not that they would have to to defeat the US.
Define "defeat". Every part of the USA was either overrun or devastated except Maryland and Delaware, yet neither the Second Continental Congress nor Washington ever seriously considered surrender.
Also a note on UK vs US shipbuilding capacity: Pre-WW1 it is actually far from certain that the USN would ever be able to catch up to the RN in a shipbuilding race as the UK at this time still posses the most shipbuilding capacity (in terms of major building facilities) in the world and has by far the largest amount of foreign investment holdings in the world which they could liquidate and use to fund a major, extended war and shipbuilding war (which they did in WW1, allowing them to heavily finance the whole Allied war effort).
If this is true then why were US war loans considered so critical? Granted, there ARE posters on AH.com who consider America's role in WWI to be completely superfluous, but they mostly include just the High Tories. Not unlike the American Exceptionalists who think that the USA was responsible for "winning"

WWII.

Also considering the gross numerical advantage the RN has over the USN in all aspects of naval combatants I cant see the USN stopping it even in an extended war, especially if the RN is supported by either (or both) the German and French Navy.
Not THAT gross, depending on the chosen year. If its 1922, forget it. Even the USN's paucity of ASW assets will have been addressed. If its 1914, then standing on the defensive, its still "forget it". Too many of the USN's older pre-dreadnoughts will still be viable for home defense, while the Royal Navy's capacity for transatlantic warfare will be mostly neutralized by the awesome level of logistics required.
All the talk about what Britain accomplished in WWI on the European Continent is meaningless. They were entering a completely friendly French logistical system with many ports available and a good dense rail network. Not to mention that:
3,000 miles of North Atlantic > 7 miles of English Channel
There was good reason why the AEF grew so exponentially fast in France in WWI while the D-Day landings in WWII took a 2 1/2 year build up.
TBH, any ATL that has Germany on the same side as France is ASB, and frankly so is Germany on the same side as Great Britain. And that's not even considering Russia, which had historically a good relationship with the USA. Meaning that if I'm the Kaiser, and I'm looking at a USA that has as its second largest racial component (after WASPs) German-Americans, with a hungry Russia to my east and a revanchist France to my west...
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.
Cold War =/= 1917
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?
By this logic Britain should have surrendered in 1940. And others here have done a better job than I could regarding the impossibilities of your redeployment numbers and timings.
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.
The time required for such a massive strategic redeployment of forces over such a restricted logistical network that would make Overlord look like a holiday ferry trip would have the "invaders" facing the same four million man army that the US Army/US Marines would have had available for 1919 OTL,
without the transit times required for transiting to American ports, loading on ship, embarking to France, crossing the Atlantic, disembarking, railing to the front, reassembling their units, marching to the front lines, and engaging the enemy!
Thank you
galveston bay
galveston bay said:
<snip>
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.
This is the real killer ITTL.
logistics-logistics-logistics
While the close blockade tactics are of the 19th Century and 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
Don't forget the Gulf & US West Coasts. Goodbye Vancouver.
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.
This fact is all too often blithely ignored/handwaved in these threads, sad to say. So damned inconvenient. Without aircraft carriers, an area in which the Royal Navy scored a distinct third pre-WWII, power projection by the RN into American home waters is problematical at best (to put it mildly).
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.
Don't forget that Halifax is at the far eastern tip of Nova Scotia, while at the far western tip the province tapers down to a narrow isthmus, vulnerable to bombing, shelling, and amphibious invasion. IOW, a major source of interdiction. Any British campaign could face a continental scale of loss of supply in wintertime due to these factors.
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.
Which won't be happening during Canada's long harsh winters.
Otherwise, the Anglo-German invasion is not going to get very far into the US before they have outrun their supply infrastructure.
Agreed
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.
Not much conjecture.
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.
Bolts from the blue are beyond impossible. Not unless the Canadian Militia all the way down to every last man in the RCMP are ready to go straight from their barracks with only the bullets and rations in their backpacks, while waiting for the British to mobilize from 3000 miles away.
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.
PLEASE read up on US mobilization times in the American Civil War, WWI, and WWII.
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...
GETTING there for defending the Maritime Provinces is one thing, transporting them in a combat capable sense across the length and breadth of North America to threaten or even invade the American heartland is another. And the Canadian LOCs along the Great Lakes (esp. in the western edges) are horribly vulnerable to severing by the US Army, which IMO will NOT be "paralyzed" by some mysterious force of inaction. Whether in terms of mobilization OR expansion.
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.
That involved friendly ports all along the way, not 12,000 miles

of mostly empty Pacific Ocean waters! Much of it presumably patrolled by the US Pacific Fleet. BTW, if the IJN lacked the ability to power project even to the Hawaiian Islands beyond an air raid (the Kido Butai had three destroyers with only 3 hours of fuel left by the time they made it home), I would imagine things would be far worse in the 1910s-20s.
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.
Geographically, the US heartland is far less threatened by an invader from Mexico than the other way around.
From the south, Mexico is all but impregnable.
From the west, its not much better.
From the east, its tough, but doable. Though Cinco de Mayo proved that even the best France could offer could be curbstomped by well led Mexican peasants!
But from the north? Mexico has always been an open door, completely indefensible. Think of a wide open bowl. All an invader has to do is whip out a spoon and start scooping.
The logistics of Northern Mexico, the situation on the ground (Mexico has always had a lawlessness problem in the North, compared to the rest of the country), plus the political chaos of what was after all the Mexican Revolution, makes for using Mexico impossible.
Far more likely that the Mexicans will, in the name of remembering the Imperial French, turn on the "Alliance" members, should they show up. Whatever Mexico City might have to say about it.
<snip>
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.
The Zimmermann Telegram alone produced national hysteria, with formerly pro-Central Powers German-Americans in the Mid-Western States retreating over to the right side of their hyphens while facing terrible treatment at the hands of their fellow countrymen (no comparison to what happened to the Nisei in WWII of course). To this day, the use of the word "hot dog" over "frankfurter" still persists. Even lifelong Anglophobic Irish-American congresscritters were forced to launch extended speeches denouncing Germany while praising Britain's "long struggle against the Hun!"
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.
Even if Neville Chamberlain were President of the United States, he would have had the US military posture at DEFCON 2 within three months of this build up. At six months, general mobilization and an all out Peacetime Draft.
Remember, all these ideas about flooding Canada with British troops would be in violation of sacred treaties between the US and Canada/Great Britain that had lasted for some four generations. You could well see the rapid construction of destroyer squadrons on the Great Lakes, and Canada's abilities to respond to that would be most limited, unless they wanted to start an invasion preemptively.
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.
Already answered.
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.
Friendly environments in France, facing demoralized Turks surrounded by Arabs that hated them, facing isolated colonial troops in Africa, and Britain LOST at Gallipoli.
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.
Only if the Atlantic Ocean doesn't exist, and North America is connected to Europe at multiple points. But, uh, that would represent a POD somewhere in the Paleozoic Era
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.
Railroads =/= ocean going ships
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?
They won't have to. Again, you are postulating the "frozen US forces theory" so common to these threads.
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.
*facepalm* Wisconsin is
slightly farther away from Germany than Belgium
<snip>If we are going pre-WWI than the requirements for vehicles is less.
And for horses, more.
It would be very difficult but I think it could be done. If you had German forces in Mexico aiding their candidate in the civil war, that could be a reasonable pretext for having a large German force in Mexico.
Total violation of the Monroe Doctrine. The only reason the Imperial French got away with this in 1861 was due to the American Civil War. Immediately after Appomattox General Grant sent Phil Sheridan straight to the Texas border with four Union Army corps (twice what the French had in all of Mexico IIRC) with the message "Get Out!" That's why in the ACW victory parades you don't see Sheridan depicted. He was busy elsewhere.
Invasion of New England from Canada
That's a very densely populated area, allowing for a well supported defense. With the level of defense factories there, no matter what military weaknesses this American Stupids ATL may have, in New England they will not be defeated.
maybe after the Brits build up in the North with the US watching them
And the US doing what in response, exactly?
then the Germans and Mexicans come over the border in the South.
Answered above.
couple with sea superiority
Where and when? Coastal Artillery remember.
then put an amphibious landing ashore to give them a third threat.
They don't HAVE an amphibious capability worthy of the name.
Not compared to the US Marines. The Royal Navy can't do everything under the sun in terms of naval warfare.
One problem I thought of with my scenario is this - if Frederick lives longer and Britain and Germany are friends do you still have a dreadnought race?
I think such questions are both outside the framework here and borderline ASB.
American issues are solved by having the worlds best rail net, and a pretty high quality water transport system as well as adequate roads.
Armies do not just require food to advance. This isn't the 19th Century when an army could carry most of the ammunition it needed for a campaign. In the 20th Century with vast numbers of more complex machines including the rifles themselves a similarly vast amount of spare parts are needed, as well as huge quantities of ammunition, fuel for motorized vehicles (Canada has no oil production of note well into the century while Mexico had few refineries), and everything else from uniforms to medical supplies.
Not to mention that Mexico doesn't have much of anything in the north.

Except rebels.
It has already been determined Canada can probably feed the troops. What is doubtful is whether it can provide everything else an army needs and whether the internal transportation of Canada or Mexico could handle the massive increase in traffic and thus stress an army needs.
This discussion thread seems to be ignoring what a horrible mess Mexico was in at the time. The Diaz dictatorship was dying, and the Mexico Revolution was about to begin.
Circa 1929, war plan red-orange is the most likely way that America could have been invaded Post 1900. The Japanese attack the American Philippines and other military installations across the Pacific. The British fight in the Caribbean while the Canadians swarm into Idaho and Maine. If the United Kingdom had went to war with the United States and Japan had honored their alliance, the United States would have lost. The United Kingdom was doing better, not with industry but with their economy. Japan's military was not as advanced but a surprise strike from three sides could compensate for that.
The IJN lacks the ability to project beyond the Western Pacific. They are no threat to the US West Coast.
Idaho is in the Rocky Mountains. Maine allows concentration of USA naval and ground forces, while this scenario ignores Canada's own vulnerabilities. Such a strategy will be followed by the Canadians the day after never. The USN is free to concentrate what ever other forces it has in the Gulf Coast against a Royal Navy that is at the other end of a very narrow tether. The US has a number of bases in the Caribbean too. They are not disappearing any time soon.
Because it's a Post 1900 POD a US invasion TL will always be near ASB. I don't think it is ASB however. The way to invade is laid out already by geography. The problem is getting the right demographics. That's way I think the best time is in the 1930s in a ATL where WW1 doesn't happen, Smaller, or America just doesn't get involved. The global economy still tanks and the dust bowl still happens as well. Mexican population growth started to boom in the 1930s.
No WWI is a VERY different world than ours. If America doesn't get involved, the Entente goes broke, and at worst Germany gets a "stalemate" ante-bellum ending. I agree the Great Depression is inevitable. But with FDR you have the Good Neighbor Policy, preventing the poisoning of US-Canadian-Mexican relations. Unless you handwave him. But you'd have to handwave the policy too. Why?
All Invasions of the US will need Mexico and Canada.
Agreed. All else is ASBed ASB.
The goal would be to capture Chicago, and New Orleans.
Handwaving the US Coastal Artillery Corps, New Orleans, very temporarily, is not ASB. Assuming the river doesn't get mined. Chicago is ASB. Thing is, there's this really big lake...

Detroit, at least, could face threats.
Control over the Mississippi River basin is then contested forcing Washington to the negotiating table.
Consider how long it took the Union to seize the Mississippi, they had the interior lines, and were coming from both directions. ITTL, you have a fully developed road and rail system, aircraft, rail guns, and troops shooting at your ships/gunboats all the way. No. Just no.
Diversionary raids would be taken on Southern California
Logistically impossible for anybody. Baja California is the ass end of Mexico, for everyone else Southern California is at the ass end of the world's largest ocean.
Was it even inhabited in the 1910s-20s?

And...strategic objective? What are the Americans to make of any possible objective in Florida?
Leave Washington and the Northeast alone to create a divide among Americans.
Google "Pearl Harbor", to learn about how disunited Americans get regarding sneak attacks...

*whew!*
edit:
Riain, I highly suggest you check out an old discussion thread on spacebattles.com, called "War Plan Orange + Red" (or was it "War Plan Red + Orange"
). Its from way back in 2009, but its pertinent here. Our own Alamo goes a long way towards describing the impossibility of such a scenario (though its different in many ways too, set in 1942!). What's pertinent is the idea of the USA doing NOTHING while the British basically send everything including the kitchen sink to Canada.
Just watch out for the postings there of three particularly nasty trolls. You'll see who I mean pretty quickly. Very conducive of creating headaches, they were.