Wow, someone called it.

[Tupsi]

When XI got DDoS'd it was by Korea due to political unrest in the region numerous years ago. In that regard it was just a cyber attack (since starting a war would have been silly because Korea would have been nuked off the face of earth by the US.) What SE did to fix that was block the specific region it was coming from, which did hurt the people not takin part in the DDoS but it immediately stopped them.

They may not do that here if it's concentrated to one specific region, but the fact it's only NA/EU says it's likely someone who got caught and banned recently or could even be the RMT retaliating, since NA/EU has the highest RMT problems.