I say “recently” in a relative way, more so countries that have split in the last century. Places like North and South Korea, Taiwan and China, former USSR states, etc.
Has enough time passed that these countries separated have major changes in their languages yet?
It is true that here in Germany Eastern and Western accents differ, however, also in between the Western or in between the Eastern accents you have quite some difference.
On the other hand I would also say that most Eastern accents share a common undertone, more so than the Western ones.