If the French only intervene in naval terms, breaking the union blockage that would make a big difference to the war. The Confederates can trade with the world, importing many of the weapons and other heavy equipment that they have difficulty producing themselves. They can use coastal traffic to ease the burden on their railways and roads. It also means that they can be a lot more secures about union landings so likely to keep control of New Orleans. As such to cut the CSA in two the union would have to fight all the way down from the north. All those steps would make its defeat markedly more difficult. Furthermore it would make it a lot easier for any Confederate raiders to operate on the high seas.
Again, lots more reading to do. I seriously don't know enough about the military situation to say what opening up trade will do. The South's armies were nearly always badly under equipped IIRC so this should be a boost for them. At the minute I'm looking at the French being able to keep the South's ports open for the whole of 1862 but starting to run into trouble in 1863 as the Passaic-class monitors start being commissioned so that by the end of the year the blockade is back in place. That's if the Passaics are a match for France's Magenta class ironclads.
There is also the political and diplomatic factor. Recognition by a major power would boost Confederate moral and make it more likely other powers would do likewise while probably further divide opinion in the north. [Some reacting angrily that a foreign power has intervened while others viewing it as more evidence that the conflict is pointless]. Also since the French will probably have an advantage in trading with southern markets that would give an incentive to other powers to seek to trade with and recognise them.
Good points. I've no idea how this might affect things like politics or elections in the North so have a lot more reading to to. As for trade I'm sure Napoleon III will arrange some sort of preferential agreement for French interests buying cotton as payback for recognition and helping lift the blockade, the fact that large amounts of this cash will be immediately spent of supplies needed for the war in France and Europe is a bonus as well. Other states will also probably look to get in on the act but I'm planning on having Britain hold back for the moment.
If France got more heavily involved, say sending a corp. over and blockading the north the war would probably be over pretty quickly. Unless this prompted a strong British reaction the north would be cut off from trade itself and more importantly a lot of its revenue.
I doubt France would do that, that's probably a little
too involved for Napoleon III. He was always looking for glory on the cheap so and with the Mexican affair about to kick off, starting to eye up Vietnam although they don't seem to have been able to decide what they wanted to do there, and having to keep a weather eye on the competition in Europe I don't think they'd chance it. At least not in the TL I'm thinking of.
I'm kind of undecided on whether the French would actively blockade the North or simply settle for recognising the South and then breaking the blockade on them under the guide of simply wanting to trade freely with them without interference from an outside power. Whilst it wouldn't make all that much difference to be honest since both nation's warships will be trying to sink each other down South I think the French would probably try to hide behind that diplomatic fig leaf. Unless someone with better knowledge says differently I'm leaning towards a generally limited active involvement of no troops and simple recognition and opening the ports, although I can't make up my mind fully on the second part.
I think the sources that says it was a cynical move, to improve the position of their navies and get some cheap diplomatic points. After the Crimean war Russia was in no real state to engage in another major conflict again. It had been shown to be seriously obsolete in its armed forces and organisation and needed a period to reform. Not to mention the debts resulting from the conflict.
Bugger. That's what I thought.
Some interesting ideas but I doubt it would be practical. The French navy would be far too strong for the Russians, who would also be isolated, other than seasonal Pacific ports in the Russian Far East, with very little logistic and repair ability. They can use the American Pacific ports, presuming the latter agree, which they probably will. However those are also fairly small and under-developed at this time and poorly defended so could suffer from French attacks as a result. Also that would expose the exports of Californian gold and Nevada silver to attack, another big source of revenue for the union.
The general idea was that the Russians wanted some way of striking back at the French and with Europe out of the question, places like Mayotte or Reunion in the Indian Ocean too far away and too heavily defended they decide to take a couple of what were fairly new protectorates that didn't have much in the way of defences or a French presence. France interfering with the gold and silver shipments is an intriguing idea.
The (
very rough) general outline off the top of my head so far is:
* President Juarez suspends Mexico's interest payments on their debts on 17 July 1861 to Spain, France and the UK and others.
* Treaty of London 31 October Spain, France and Britain agree to put pressure on Mexico through blockades.
* Mason and Slidell miss the RMS Trent and instead hop the French Ship (FS) Rhone.
* On November 9 the USS San Jacinto stops the Rhone and a search party is sent across and boards her. During the search the French Captain Jean-Pierre Martin is much more confrontational getting up close and shouting in his face so Lt. Fairfax gives him a small shove to get him away, he trips and bangs his head suffering what is thought to be a concussion. Mason and Slidell are removed as in IOTL and the USS San Jacinto goes on its way to great acclaim in the US.
* November 10 Captain Martin continues to be groggy and unresponsive, passing away in the evening due to what is later found to be internal bleeding.
* Mid-November news of the seizure and death of Captain makes its way back to France. The public and politicians are outraged that a US warship has stopped a French one on the high seas, boarding and seizing passengers and killing the captain in the process, there is a massive public backlash against the Union. "After everything we did to help them during their Revolution..."
* Napoleon vacillates, whilst he can't go against public opinion he also doesn't want to do anything major without the accompaniment of the UK. The British state that they wont go along with any reprisals and that they should sort it out though diplomatic channels. Diplomatic exchanges are sent to the Union at the start of December however matters are inconclusive and drag on.
* British, Spanish and French fleets arrived at Veracruz, between 6 January and 8 January 1862 to blockade Mexican ports to force their restarting debt repayments. The Union do not approve considering it close to a violation of the Monroe doctrine which further complicates dealings over the Rhone affair, the French have been much more combative than Britain IOTL and the Union pretty much tells the French to go shove it.
* City of Campeche surrenders to the French fleet on 27 February with a French army commanded by General Lorencez arriving on 5 March. Union goes ballistic at all out violation of the Doctrine.
* Having been advised that his Second Mexican Empire scheme will
not be well received by the US and will more than likely countered with everything short or active involvement once the civil war is concluded Napoleon III decides that a weakened Union and friendly Confederacy is therefore the best result. On 1 March he officially recognises the CSA and announces that warships will be sent to make sure that French traders will not be molested when trading with a legitimate country, effectively saying they will break the Union blockade if challenged. Large sections of the French fleet are sent to the coast of the Americas, they will not however be blockading Union ports though simply escorting French shipping.
* Realising what the French are up to in Mexico the Spanish and British withdrew their forces on 9 April and fully leave by 24 April, this attitude doubly reinforced when news of French recognition of the CSA reaches them. French intervention in Mexico goes pretty much as IOTL to begin with.
* Continued later.