After Mr. Terrific causes "The Flash" and a crate to fall, everything and everyone else who falls do so without the noise of their impacts and can't be seen a moment later.
Since the Kasnian civil war happened a relative short time ago (two years at most), the chances of a reunited Kasnia joining the European Union are extremely low, since admission requires several criteria, like economic and political stability and care of human rights. Also, EU membership does not make a nation immediately part of the Eurozone: this also requires a list of criteria to fulfill. Due to all the strict demands, both processes often take years.