Other US Civil War Alliances?

The Primary ATL alliances for either side in the US Civil War are Britain and France with the Confederacy. I *think* it may be possible for Russia to get involved elsewhere in the world against Britain *if* the British get involved enough to be weaker someplace like Afghanistan or starting Crimean War II. Whether that would end up as a formal alliance between the US and Russia, I don't know.

The Spanish were involved in various (almost random) military adventures in the 1860s including Morocco, Chile, Peru and Indochina, can we get them involved on the Confederate side? (The US forced to either allow Havana as a jumping off point for Blockade Runners or to invade/blockade Cuba?)

I can't see any other European Power getting formally involved, though I could see observers from Prussia ending up on one side or the other (probably Union).

My other question is whether we can get a formal alliance during the Civil war between one of the two sides in the US Civil War and one of the two sides in Mexico? I think the most likely of these would be between Juarez and the Union.
 
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