“Nobody could look at a map of Europe in 1 CE and predict where all the borders will run in 2025 CE. ” The Roman European provinces of 1 CE (and the national boundaries at the time) have pretty similar borders to the major states of 2025 CE.
Even with the Hapsburgs ruling Austria for 700 years, afterward it still chose to became part of the German state in 1918-9, and it willingly did became part of the state from 1938-45. If the Soviets had decided to merge East Austria with East Germany, there’s every chance the same would have happened in the west. (Britain wanted Austria to merge with Bavaria). And then if not for the EU, the Austrian state of our timeline may well have joined Germany after the fall of the wall.
The poem is well worth publishing independently of this post.