Why would you conflate hostile foreign power and being at war? There is a difference here between necessary and sufficient conditions. The presence of hostile foreign powers with whom we are not at war is evidence enough.
First of all, my whole posting was tongue-in-cheek, which everyone else seems to have gotten.
Anyhow, does it makes sense that "A formal declaration of war" has somewhat more legal force than "An Atlantic headline writer declaring them a hostile foreign power" ?