All we have here is an announcement. Seriously doubt this was the "official" firing, hiring or promoting of anyone. The statement in the article isn't even from Tillerson, so we don't really know.

> Other nations are not going to read the US law first before deciding if the declaration was or not real

There's a lot more formality to declaring war, for any nation. Not to mention the lack of anything else to support such a statement, like an actual press conference or public statements, media attention or, you know, actual military movement which all capable nations track constantly.