Wiktionary
on the defensive
prep.phr. prepared to defend or protect against criticism, attack or aggression.
Usage examples of "on the defensive".
Generals on the defensive have often trusted, is still, if we would be clear and exact, only a rare occurrence in history.
From time immemorial, only great victories have led to great successes on the offensive side in the absolute form, on the defensive side in a manner more or less satisfactory.