风云突变

jú shì fēng yún tū biàn zhàn zhēng yī chù jí fā

局势风云突变，战争一触即发。

A hair-trigger situation has been created which could lead to an outbreak of war at any time.

lián hé zhèng fǔ de chū xiàn hái yì wèi zhe bái tīng nèi bù fēng yún tū biàn

联合政府的出现还意味着白厅内部风云突变。

The arrival of the coalition also meant that the climate in Whitehall changed overnight.