4 Bible Verses about Political Alliances, By Oaths

So Jonathan made a covenant with the house of David, saying, Let the LORD even require it at the hand of David's enemies. And Jonathan caused David to swear again, because he loved him: for he loved him as he loved his own soul.

Now therefore swear unto me here by God that you will not deal falsely with me, nor with my son, nor with my son's son: but according to the kindness that I have done unto you, you shall do unto me, and to the land in which you have sojourned.

And they said, We saw certainly that the LORD was with you: and we said, Let there be now an oath between us, even between us and you, and let us make a covenant with you; That you will do us no hurt, as we have not touched you, and as we have done unto you nothing but good, and have sent you away in peace: you are now the blessed of the LORD. And he made them a feast, and they did eat and drink.read more.
And they rose up early in the morning, and swore one to another: and Isaac sent them away, and they departed from him in peace.

And Joshua made peace with them, and made a covenant with them, to let them live: and the leaders of the congregation swore to them. And it came to pass at the end of three days after they had made a covenant with them, that they heard that they were their neighbors, and that they dwelt among them. And the children of Israel journeyed, and came unto their cities on the third day. Now their cities were Gibeon, and Chephirah, and Beeroth, and Kiriathjearim.read more.
And the children of Israel struck them not, because the leaders of the congregation had sworn to them by the LORD God of Israel. And all the congregation murmured against the leaders. But all the leaders said unto all the congregation, We have sworn unto them by the LORD God of Israel: now therefore we may not touch them. This we will do to them; we will even let them live, lest wrath come upon us, because of the oath which we swore to them.