When people already belong to the same country, party, team, church, or family, but they cannot agree and cannot work with each other, we say they are disunited. The important part is that they are supposed to be on the same side; that is what makes the split a problem, not just a difference of taste. Newspapers and speeches use it about governments and political parties that pull in two directions. It sounds a little formal. In ordinary talk you might just say they are split, they cannot get along, or they are at odds. You can also use it more quietly for a workplace or a family that has broken into camps. It is an adjective: a disunited party, a disunited country. Though actually, being disunited is not the same as being enemies from the start — the hurt is that they were meant to act as one, and they are not.

不團結的、分裂的