First, all commitments have the following processes that govern them: creation, maintenance, and change. This can be made more complex but not much simpler. Everything else about commitment is whether you honor it or not, and I'm not being moralistic with the concept of honor. To honor a commitment is to keep one's word to it and when that doesn't happen to have the integrity to deal and own the "what and why" of ones word not kept.
This typically leads into a swamp infested with prejudices and/or beliefs wrapped up in morality, truth, and right/wrong. This in turn accounts for much of humanity's fascination with religion, ethics, morals, culture, clans, clicks, etc. (I have no issue with any of these in general.) However, they do seem to be ever present when the worst poop in the world occurs. I'll leave that branch of the human social commons to those who find it productive to use as means of . . . whatever, while noting how often often it involves deciding how others ought to live their lives with only one concern: That 'they the deciders' approve or minimally tolerate those lives for which they have little concern for but to exercise their desire for control.
If you aren't totally po'd by now or otherwise disinterested, then my answer is that commitments are artifacts of agreements we have made explicitly and/or implicitly with others. To put it into simpler terms: Giving our word.
When it comes to our word, the matter is simple:
1) we can give it,
2) we can keep it,
3) we can honor it when we can't keep it by owning that are we unable to keep it and accepting the consequences both for the giver and the receiver, and
4) we can dishonor it by breaking it.
Further, the circumstances of ones word do not define ones word. Only the four areas noted matters as to how your word exists in the world, and any form of coercion applied to get, change, and/or break ones word invalidates that ones word has been given. It has not; it has been coerced.
Rachel