One way to make for a more balanced contest is to bring in foreign intervention - one of the great navies who could provide a more equal opponent to the United States. I am going to run through the possible white knights and consider the following questions.
- Does the power have the ability to intervene?
- What would it take to bring about intervention?
- How would the intervention unfold?
As to the ability to intervene, obviously the Royal Navy had the ships and the men and the money too! More over they had bases and squadrons on site for North American operations (Jamaica, Bermuda and Halifax) and Asian operations (Hong Kong).
However, I would consider British Intervention as being unlikely. There was little public or governmental sympathy for Spain and no real reason to fight the US. It would take a combination of real skilled diplomatic pressure from Spain and really stupid moves on the part of the US to bring this about.
Operationally, if the Royal Navy came into play it would likely be a game-ender, much as the Dardanelles operation stopped the Tsar's army at Constantinople in 1878. Ship for ship the US navy could but a good fight, but the Royal Navy was far too big to defeat. Plus the British cruiser squadrons could sweep US shipping off the table and bring about a negotiated settlement without getting the battle fleets involved at all. British intervention would lead to something much like the War of 1812 (at least at sea), but with pre-dreadnoughts instead of frigates.
This to me is not an option. We would have to balance off the RN with further European intervention, at which point we're no longer looking at the Spanish American war!
This is an attractive option. The French navy certainly had the ability to intervene as they still stood at number 2 in 1898. They had the battle fleet and cruisers to scare the US without overpowering them. Furthermore, bases were available in the Caribbean and at Saigon in Asia the latter with a squadron of ships.
It is also easier to see French involvement. There were stronger ties with Spain, and a bit of yellow press journalism might whip up some Latin aggression versus an Anglo-Saxon power. The US came close to giving them a cassus belli as they damaged a french cruiser (very slightly) when Sampson bombarded San Juan Puerto Rico (see wikipedia entry). Expand this into dead matelots (or dead civilians and government officials) and let wounded Gallic pride take over!
The intervention also makes good gaming possibilities both in the Caribbean and the Far East. I would see a reinforced China squadron moving on Dewey at Manila, the transfer of battleships to the Caribbean and cruiser operations off the eastern seaboard. In every case, the US Navy would have had a fight on it's hands.
Well that's enough for now. Still to be considered are Germany, Russia, Japan, Austria-Hungary and the South American navies.