compel 指在法律、权力、力量或行动等的驱使下被迫而为。
force 指用个人意志、权力、权威或暴力等，迫使他人改变看法或做本不愿做的事。
constrain 侧重施加约束力或有约束作用的影响，也指环境对人强加的影响迫使人去做某事，尤指受良心、情感等内在力量驱使去做某事。
oblige 指由于生理上或道德上的需要，促使某人做某事，也指有权威的人或机构迫使某人做某事，还可指在特定情况下被迫作出的反应。
参考例句
1. Circumstances will force us finally to adopt this policy. 环境将迫使我们最终采取这项政策。
2. The heart is not conquered by force, but by love and tolerance. 心不是靠武力来征服的，而是靠爱与宽容来征服的。
3. They have not the same force or rapidity, and do not produce the same expression. 它们没有她们的那种力度和速度，就不能产生同样的表现力。
英英解释
n.
1. a unit that is part of some military service
2. one possessing or exercising power or influence or authority
3. (physics) the influence that produces a change in a physical quantity
4. group of people willing to obey orders
5. a powerful effect or influence
6. an act of aggression (as one against a person who resists)
7. physical energy or intensity
8. a group of people having the power of effective action
9. (of a law) having legal validity
10. a putout of a base runner who is required to run; the putout is accomplished by holding the ball whi v.
1. to cause to do through pressure or necessity, by physical, moral or intellectual means :
2. urge or force (a person) to an action; constrain or motivate
3. move with force,
4. impose or thrust urgently, importunately, or inexorably
5. squeeze like a wedge into a tight space
6. force into or from an action or state, either physically or metaphorically
7. do forcibly; exert force
8. cause to move by pulling
9. take by force
