Earlier quoted context omitted.
You example doesn't make sense for this situation. It's between two people and things they did. However, The OP isn't the US government and hasn't committed war crimes (I assume). Also your example isn't even whataboutism which is defined as "the technique or practice of responding to an accusation or difficult question by making a counteraccusation or raising a different issue." What other accusation or difficult qu…
Holding another group or person to the same/similar standard is often called "whataboutism" though. I will concede that that is probably misplaced (and malicious) application and not what was originally intended. That's why claims of hypocrisy against the other party, backed up with examples of the same behavior in other situations from them instead of you, can be cheaply dismissed as "whataboutism".
However... visa V mastercard , using whataboutism is valid in this situation. Bringing up something the US government did in the past to silence the criticism of a US citizen to another countries actions is wrong.
EDIT: Just another thought about your example. There isn't even hypocrisy. Person B lent money to A and A paid it back, then Person A lent money to B and B didn't pay it back.
- B doesn't pay back money
- A pays back money
There's no contradictions in their actions.