Those are the steps any country takes when it goes to war. They set up a blockade, if it's possible and likely to help, and they go to the bankers for money, since war costs money. I suspect even Jeff Davis went looking for loans.
BTW, if you did loan him any money, you won't get it back: Tampa Sued to Collect on 147-Year-Old Promissory Note Worth Millions. Section 4 of the 14th amendment invalidates debts "incurred in aid of insurrection or rebellion against the United States," as well as claims for compensation "for the loss or emancipation of any slave."
And the answer to our trivia question "Who was the guy who looked at the same data as Kettell and concluded that the economy of the Deep South was perilously dependent on New York?" is Stephen Colwell auther of The Five Cotton States and New York, or, Remarks Upon the Social and Economical Aspects of the Southern Political Crisis (1861), though I would also accept Samuel Powell, author of Notes on Southern Wealth and Northern Profits (also 1861).
You said: “Those are the steps any country takes when it goes to war.”
That is right and exactly the path that Lincoln took to start the war.