Which is why we invented laws and legal systems to codify such things.

Did you commit a crime, yes/no? Let's bring it to trial.

The circumstances are messy in all real world instances, but the outcome is binary.

Refusing to even put a president on trial is more black and white, because it's a clear "no, not illegal" without even discussion.

Courts don't even decide yes/no. Maybe is an outcome. We don't know is also an outcome.

Doubly so since almost everyone stopped bothering to declare war after WW2.