Seine Rede war eine Kampfansage an die Opposition.

His speech was a declaration of war against the opposition.

Die Preissenkung der Supermarktkette war eine klare Kampfansage an die Konkurrenz.

The supermarket chain's price reduction was a clear challenge to the competition.

Der Boxer schickte vor dem Kampf eine Kampfansage an den Weltmeister.

The boxer sent a declaration of war to the world champion before the fight.