loose cannon

The Japan Times Online Feb.6の記事 'Trump presidency triggers doomsday inflation' にトランプ大統領を表すのにピッタリと思える表現がありました。
U.S. President Donald Trump is a loose cannon, but he's not the Apocalypse, and most other world leaders are still grown-ups.
ガタがきている様な大砲ではぶっ放されたら砲弾はどこに飛んでいくのか分かりません。物騒ですね。
・Oxford English Dictionary: An unpredictable or uncontrolled person who is likely to cause unintentional damage.: Obviously we were all put on alert in case there was a loose cannon targeting skydivers.
・Collins Dictionary: a person or thing that appears to be beyond control and is potentially a source of unintentional damage: A preposterous seventeenth century opportunist, a loose cannon , an incorrigible hypocrite.
明日から又南の島に（外国ではありません）旅行に行くので、ブログはしばらく休みます。