思前想后

to consider past cause and future effect (idiom); to think over the past and future / to ponder over reasons and connection

to think / to consider

front / forward / ahead / first / top (followed by a number) / future / ago / before / BC (e.g. 前293年) / former / formerly

to think / to believe / to suppose / to wish / to want / to miss (feel wistful about the absence of sb or sth)

to think (about) / to think of; to devise / to think (that); to believe (that) / to desire; to want (to) / to miss (feel wistful about the absence of)

empress / queen / (archaic) monarch / ruler

back / behind / rear / afterwards / after / later / post-