The Federal government's desperate struggle, funding revolutionary organizations in various countries to incite uprisings, was naturally clear to the governments of those nations.
If the news were to leak, the Northern government might not be finished, as the various countries still needed a divided United States and wouldn't squish it with a single blow, but President Lincoln's current administration would certainly be done for.
Including the capitalists who supported them, they would all abandon them at the first opportunity, and possibly even jump out to trample them further.
There was no way around it; with the great powers being unreasonable, if they had a valid point, would they let it go? Without a reasonable explanation to England, France, Austria, and Spain, the Federal government simply could not get by.