FORCE, COMPEL, COERCE, CONSTRAIN, OBLIGE mean to make someone or something yield.

FORCE is the general term and implies the overcoming of resistance by the exertion of strength, power, or duress.

e.g. forced to flee for their lives

COMPEL typically suggests overcoming of resistance or unwillingness by an irresistible force.

e.g. compelled to admit my mistake

COERCE suggests overcoming resistance or unwillingness by actual or threatened violence or pressure.

e.g. coerced into signing over the rights

CONSTRAIN suggests the effect of a force or circumstance that limits freedom of action or choice.

e.g. constrained by conscience

OBLIGE implies the constraint of necessity, law, or duty.

e.g. felt obliged to go

verb with object and infinitive

make (someone) legally or morally bound to an action or course of action:

｟かたく｠ ; 〖通例be ～d〗 «…することを» 強制される, 義務づけられている, やらねばならない «to do» (!進行形にしない)

e.g. doctors are obliged by law to keep patients alive while there is a chance of recovery.

with object do as (someone) asks or desires in order to help or please them:

｟かたい書｠ «…で» 〈人〉を喜ばせる, 手助けする; 〈人〉に親切にする, 恩恵を施す «with, by» (→ 分詞obliged)

e.g. oblige me by not being sorry for yourself

«…で/…することで» 手伝う, お役に立つ, 好意を示す «with/to do» ; 要望に応える

e.g. no object : tell me what you want to know and I'll see if I can oblige.

(be obliged) be indebted or grateful:

e.g. if you can give me a few minutes of your time I'll be much obliged.

with object archaic bind (someone) by an oath, promise, or contract:

e.g. my father had obliged me to the improvement of my stock.

obliger noun

Middle English (in the sense ‘bind by oath’): from Old French obliger, from Latin obligare, from ob- ‘towards’ + ligare ‘to bind’.