軽挙妄動
kei.kyo.mou.dou

Literally: light (as opposed to “serious”) – action – delusion – motion

Alternately: Rash, unthinking action. Doing this and that on impulse, without planning or consideration. Indiscriminate wild flailing.

Notes: Despite their relatively similar meanings, replacing 妄 with homophone 盲 (“blind”) is considered an error.

Perhaps because human history is full of this kind of behavior, there are a number of synonyms, including 短慮軽率 and 付和雷同. Fortunately, there are also antonyms, including 熟慮断行 and 思慮分別.

The blog that made this association was talking about Japanese politics, but it does quote Arendt as saying that the Government is not a playground for children.