Idiom: Cross the Rubicon
Cross the Rubicon is an expression that means once you do something, you cannot undo it.
It refers to Julius Caesar returning to Italy and fording the Rubicon River with his army.
It was illegal for a Roman general to bring his army into Rome at the time.
Once Caesar had brought his army across the Rubicon, he could not second-guess himself.
He had broken the law, and his only choices were to fight or run away.
You’ll have to do some research to understand why Caesar crossed the Rubicon with his army.
Anyway, in modern times the idiom is used quite often.
Most recently, North Korea crossed the Rubicon with its intercontinental missile tests.
Now there is no going back to a non-nuclear capable North Korea.
We all have to deal with it in the best way we can.