(idiomatic) After a plan against an enemy is drafted, there will be unexpected elements from the opposition that will call for improvisation.

(US, law enforcement, dated) A person who ranks highest on the federal government's prioritized list of wanted criminal fugitives.

(idiomatic) To cause problems for one's self, act contrary to one's own interest, self-sabotage.

Third-person singular simple present indicative form of be one's own worst enemy

simple past tense of be one's own worst enemy

Alternative form of perfect is the enemy of good

past participle of be one's own worst enemy

present participle of be one's own worst enemy

When you notice that an enemy is making an error, take care not to interfere with the enemy from completing it so you can take advantage at the right time.

Indicating that one's close associates prove more adversarial than one's opponents.