矢在弦上

Explanation: Arrow has been upon the string. Compared to such circumstances, had to take some action. 　　Source: Three Weichen Lin "as Yuan Shao Xi Yuzhou" note cited "Wei Zhi": "arrow in the string can not not fat." Thesaurus:  to fight up and down the country, the glint and flash of cold steel, as an arrow on the straining cordready to start, have fought a hundred battles, pelter, throw aside the writing brush and join the army, Disposable paper on the arms, fight in one place after another the winged steed, Nanzheng the Northward Expedition (inthe history of the Republic of China), Turn the Big Dipper the winged steed Antonym Group:  stick together, A truce by, Anjiaqinbing, take off the armour and return to the farm, take off the armour (literally) to throw away weapons--to effect a cease-fire or truce