I have a simple question about the rules-based order

https://www.youtube.com/watch?v=-6Wu0Q7x5D0

Here is a 19 minute video of the world's borders over time. I don't expect anyone to watch it all, but it seems to me that at about minute 18 of the video (mid-1950s), the worlds borders dont move around as much.

Why is that?

What might make them move around again?

Is there any likelihood that the combined geopolitical events in Europe, the Middle East, and the Indo-Pacific may cause the world's borders to start acting all funky again soon?

To define the aforementioned "geopolitical events" and regions further:
Europe: The Russia-Ukraine war, but also more broadly, the potential rise of nationalism/populist regimes in Europe and decline of liberal democracy)

The Middle East: The Israel-Palestinian-Iranian conflict, but also more broadly Iranian proxies (Houthis in Yemen, Assad regime in Syria, Hezbollah in Lebanon) and also the always-fragile Sunni Arab regimes and perceived unchecked Iranian expansion

Indo-Pacific: (China gaining in capability and influence, Taiwan, South China Sea, Philippines, Vietnam, etc)

I'm probably missing a few.