Why they are fighting overseas in Israel?

Genesis 16
King James Version
16 Now Sarai Abram's wife bare him no children: and she had an handmaid, an Egyptian, whose name was Hagar.

2 And Sarai said unto Abram, Behold now, the Lord hath restrained me from bearing: I pray thee, go in unto my maid; it may be that I may obtain children by her. And Abram hearkened to the voice of Sarai.

3 And Sarai Abram's wife took Hagar her maid the Egyptian, after Abram had dwelt ten years in the land of Canaan, and gave her to her husband Abram to be his wife.

4 And he went in unto Hagar, and she conceived: and when she saw that she had conceived, her mistress was despised in her eyes.

5 And Sarai said unto Abram, My wrong be upon thee: I have given my maid into thy bosom; and when she saw that she had conceived, I was despised in her eyes: the Lord judge between me and thee.

6 But Abram said unto Sarai, Behold, thy maid is in thine hand; do to her as it pleaseth thee. And when Sarai dealt hardly with her, she fled from her face.