万事俱备，只欠东风

wàn shì jù bèi, zhǐ qiàn dōngfēng

[everything is ready, and all that we need is an east wind; all is ready except what is crucial] 指三国时周瑜火攻曹营, 一切都准备就绪, 只欠东风尚未刮起, 不能放火。 比喻办事的其它条件均已成熟, 唯一还少一条就能成功