...this is an idea I had around the time I was off my rocker a few days ago.
Suppose some bunch of Communists in America buy a bunch of lottery tickets or something and come across a vast sum of money. Now completely out of the blue they get the opportunity to buy two old car transporter ferries that are being decommissioned in New York City. (I don't care why, it's just what played into the scenario) They also buy an Coast Guard revenue cutter, and a 3-inch gun to put on it. (I don't care where, just suppose it's magic)
They make a deal to spend the rest of the cash as part of a scheme with French Communists that will buy four FT-17 Renault tanks and have them waiting at La Rochelle along with arms and ammunition.
So they set off with 400 American and Canadian volunteers, along with another 300 in a third conventional transport. They have a rough plan: pick up the FT-17s and supplies a La Rochelle along with some fuel for the ships and further volunteers and orders. Then, they'll make an amphibious landing on the coast of Nationalist Spain in a daring thrust to break the Fascist stranglehold.
So...where do they land this small and foolhardy force, and what good will it do when it gets there?