be on the offensive

act or be ready to act aggressively

處于攻勢，（準(zhǔn)備）展開攻勢

go on (to 或 take) the offensive

take the initiative by beginning to attack or act aggressively

發(fā)起進攻，主動進攻

security forces took the offensive ten days ago.

安全部隊十天前發(fā)起了進攻。