Translation:

9. If two parties among the Believers fall into a quarrel make ye peace between them: but if one of them transgresses beyond bounds against the other then fight ye (all) against the one that transgresses until it complies with the command of Allah; but if it complies then make peace between them with justice and be fair: for Allah loves those who are fair (and just).

Notes (Tafseer)

4927. Individual quarrels are easier to compose than group quarrels, or, in the modern world, national quarrels. But the collective community of Islam should be supreme over groups or nations. It would be expected to act justly and try to compose the quarrel, for peace is better than fighting. But if one party is determined to be the aggressor, the whole force of the community is brought to bear on it. The essential condition of course is that there should be perfect fairness and justice and respect for the highest principles; for Islam takes account of every just and legitimate interest without separating spiritual from temporal matters. The League of Nations failed because these essentials were absent and today the United Nations fails for the same reason.