Tit for tat: (n.) an equivalent given in return (as for an injury); retaliation in kind; something bad that you do to someone because they have done something bad to you 以牙還牙;同等報復

A tit-for-tat action (Adj.用法) is one where someone takes revenge on another person for what they have done by doing something similar to them. 以相似手法回敬別人,一報還一報

Examples: 1) He hit me, so I hit him back—it was just tit for tat.

2) I told her if she did me any harm, I would return tit for tat.

(BBC, 2018/3/30) Spy poisoning: Russia expels 60 US diplomats in tit-for-tat measure

Russia has expelled 60 US diplomats and closed the St. Petersburg consulate in a tit-for-tat response to US action over a spy poisoning case in the UK.

Russia’s foreign minister said other countries that expelled Russians could expect a “symmetrical” response. The move comes amid a row over the nerve agent attack on a former Russian spy and his daughter in the UK.

俄國驅逐了六十名美國外交官員，並且關閉美國駐聖彼得堡領事館，以對美國因為英國間諜下毒案而採取的措施表示報復。俄國外長指出，其他驅逐俄國人的國家也會獲得[對稱的]待遇。俄國這些措施起因是英國一名前俄國間諜和他女兒遭到神經毒氣的攻擊。

(The Guardian, 2018/07/07)

The United States and China have imposed tit-for-tat tariffs as fears grow over the damage to global economy. The trade war between the US and other major economies escalated on Friday after Washington and Beijing launched punitive import tariffs on $34 billion worth of each other’s goods.

While economists say the consequences of a spat between the world’s two largest economies can be contained for now, there are fears that Donald Trump’s stance on trade could cause serious damage to the global economy.

美國和中國相互實施報復性關稅，讓舉世擔憂這對全球經濟的傷害。美國和其他經濟大國的貿易戰爭周五升高型態，華府和北京同時展開對於對方價值三百四十億美元的貨物，課以懲罰性關稅。

雖然經濟學家表示，這兩個世界最大經濟體之間的爭執暫時可獲控制，但他們仍恐懼川普總統在貿易方面的立場，會給全球經濟帶來嚴重傷損。

Photos: the print, thai residents

Sounds (中文解說): ICRT podcast