If the United States had stayed completely neutral throughout the entire course of WWI, trading with both sides but never entering the war or directly participating in the peace negotiations, how would the war most likely have gone? Would Germany's Spring Offensive have succeeded without American troops in France? Would the Entente have won, but have taken longer to do so? What might be some of the wider effects?
(Note: I'm not interested in discussing how likely American neutrality was or how it might come about-consider it handwaved for the purposes of this thread. I'm more interested in how WWI would have gone without America.)
As has been said, it's unlikely the war would have lasted until 1918. Between financial exhaustion of ALL the Entente powers, famine in France and Russia, the collapse in Russia, and the French Army Mutiny, the Germans will be in position to pull off a victory. Provided they can tone down their own very outrageous demands for peace.
The Royal Navy would say "Bring it on, Yankee boys." The Army would first figuring out how many divisions it can ship over to Canada before the USA joins the Central Powers, which by forcing the blockade it is in effect doing.
To force the blockade is going to require the RN and USN to fight it out. Irrespective of the quality of the ships and commanders, Britain has the advantage that she is fighting in home waters and not 3000 miles away. Whilst most US dreadnoughts can cross the Atlantic and back, long times at combat speeds will cut into their range to the point of needing refuelling. If the RN locate and sink the oilers, the USN will have to smartly retreat.
All this assumes an aggressive US stance. In fact, between the British and Americans, it is the aggressor who loses. The factors you raise are just as applicable for fighting it out in North America, where once the US Army and Marine Corps are mobilized Canada will be all but defenseless, save in the Maritime Provinces, and for a time, Quebec.
And as to ships, by this time the US Navy had reached qualitative equality with the Royal Navy, and even quantitative if you disallow the older worn out pre-dreadnoughts. Besides, sending in a British fleet big enough to engage the US in it's own home waters would risk uncovering the German High Seas Fleet, meaning opening up Britain's own home waters, which would have been unthinkable.
Ironically, if human nature and history is any guide, it's likely the British might have tried to split the difference, which would have been disastrous for them.
The British had no divisions to spare, including the Canadian divisions, which were locked in trench warfare in Europe. Also the problem is getting them to Canada...<snip>
Pretty much.
On the Army and Canada I certainly agree. In fact it is one of the same reasons why Britain declined to support the Confederacy some fifty years earlier.
On the RN, I beg to differ. As long as either the USN or the High Seas Fleet are in port the RN can take the other. Obviously what it can not do is if the USA and Germany co-operate at least at sea.(1)
1) The entire US East Coast, Gulf Coast, Panama Canal, West Coast, and Hawaii are a helluva lot harder to manage in terms of "keeping them in port" than the single port of Wilhelmshaven.
True enough, but that choice is up to the RN and it can't have both. Co-operating or not if the RN chooses to keep its thumb on one then the other is going to operate with a freedom that would ruin Britain’s naval strategy. I don't think either side (US or UK) would or could let things get to actual fighting ... but playing the card here if they did then the UK is stuck. If they pull ships to engage the US in the Western Atlantic then the German fleet is going to be at liberty to do damage ... if they leave the USN to stop the British Merchant Marine ... then the islands and allies go hungry.
Exactly. The RN could keep up the blockade of the Germans, but they flat out didn't have the forces remaining to engage the USN in American waters. The aggressor loses, whoever it might be.
For much of the year they wouldn't even need to do that.
During the Winter months, the St Lawrence Seaway was frozen, so Canadian exports to Europe had to go through the United States. Thus they could be interdicted without firing a shot.
No doubt the US would pay for the grain at market rates (her own 1916 harvest had been very poor) rather as the British did for goods seized by the blockade. The Canadians would be furious but have little choice in the matter.
The St. Lawrence Seaway did not even open until 1959.
So...twelve months a year?
I don't think anyone's mentioned oil yet.
Iirc in 1917 the world's main sources of oil were the US and Mexico. And their oil was vital to the RN. In Spring 1917 reserves were so short that the Grand Fleet was ordered to conserve it by cruising at three-fifths normal speed. And when America entered the war, GB had to ask the USN to send over only its old coal-burning vessels, as no fuel oil could be spared for the modern ones.
Should America stop oil exports, and persuade or force Mexico to do the same, the RN is in deep doodoo.
Coal would be an issue too. The USA is the Saudi Arabia of coal.
Also, Mexico was in a state of a long revolution at this time, so I don't know how well the oil wells would be operating.