How to say "aggression" in Japanese

• 侵略しんりゃくJLPT N1approx.Common
  noun, suru verb, transitive verb, intransitive verbAggression in the sense of a large-scale attack on another country; it strongly suggests an unjustified invasion. This is the word you want for political or historical talk of one nation's aggression against another.
  ヒトラーは１９３９年ねんにポーランドを侵略しんりゃくした。↗

  Hitler invaded Poland in 1939.
• 攻勢こうせいCommon
  nounAggression as an offensive movement in fighting, the act of pressing an attack rather than the act of invading. Typical in military reporting, as in an army taking the offensive or stepping up its aggression.
  われわれは敵てきの攻勢こうせいに後退こうたいした。↗

  We recoiled from the enemy's offensive.
• 侵入しんにゅうJLPT N2approx.Common
  noun, suru verb, intransitive verbAggression in the sense of an incursion or raid, entering another's territory or space. It focuses on the intrusion itself rather than the whole campaign, and also covers incursions into places like computer systems.
  「ピッキングの道具どうぐ無なしで、どうやって侵入しんにゅうした？」「トイレの窓まどがあいた」↗

  "With no picks how did you break in?" "The toilet window was open."
• 火の手ひのてCommon
  expression, nounAn idiomatic expression meaning attack or aggression, literally 'tongues of flame'. It is used figuratively, for the fighting or offensive spreading or flaring up, and is seldom the neutral word for aggression as a concept.

Use 侵略 for aggression against a country, 攻勢 for military offensive action, 侵入 for entering or incursion into territory, and 「火の手」 idiomatically for the outbreak of hostilities.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 侵略しんりゃくinvasion (e.g. of a country)
• 攻勢こうせいoffensive (movement)
• 侵入しんにゅうinvasion
• アグレションaggression
• 戦争挑発せんそうちょうはつaggression
• 攻撃性こうげきせいaggressiveness
• 火の手ひのてattack