I went to Wikipedia to refresh my memory of the Articles of Confederation. It’s been a while since I’ve studied American history,

Basically, the AoC made it nearly impossible to negotiate treaties with foreign powers, and to deal with international trade in general. Each state felt they could make their own agreements with Britain, for example, leading to chaos.

There was no chief executive and no national judiciary, too.

en.wikipedia.org

The CSA experienced the same problems, so they eventually ended up replicating the federal system.