What Do Taxes Have To Do with Trading with The Enemy Act?

What Do Taxes Have To Do with Trading with The Enemy Act?

Remember, FDR said nobody can be compelled to pay the national debt. This also has ramifications when we know about the "Trading With The Enemy Act".
 
Abe Lincoln was quoted as saying, "It denounces as public enemies all who question its methods or throw light upon its crimes. I have two great enemies, the Southern Army in front of me and the bankers in the rear. Of the two, the one at my rear is my greatest foe." What "enemy" could the average American be "trading" with to subject him or her to the Trading With The Enemy Act? Maybe the same enemy which Abe was talking about?