Jerusalem - Bethlehem Spring
Bethlehem is only six miles south of Jerusalem. Amarna letter # 290 refers to it as "a town of the land of Urusalim" and complains that it has joined the enemy of Pharaoh. Jerusalem was the important city in the region, and Bethlehem was important to it for strategic reasons. Despite its natural defenses, Jerusalem had to worry about the armies of Egypt or Mesopotamia, which would likely approach from the Great Trunk Road on the coast.
There were two likely approaches from this road; both were ridges unbroken by wadis. (See map below.) One ascends through lower and upper Beth Horon (the Beth Ur's of today) to the central Benjamin plateau, north of Jerusalem; here it meets the single north-south road of the central range. The second ridge ascends from the Valley of Elah, intersecting the main road southwest of Bethlehem. (It is the ridge that Saul is defending in 1 Samuel 17:1-3.) Jerusalem needed a buffer in the area between itself and this intersection. It did not always control Bethlehem (e.g., in its Jebusite period), but it thought it should: hence the complaint in the Amarna letter. Thus, Bethlehem always had the strategic value that Solomon's son Rehoboam recognized when including it in the belt of fortified cities protecting his capital. (2 Chronicles 11:5-10) It was a last-chance bulwark in the south.
Once the decision has been taken to establish a bulwark between Jerusalem and the intersection, a small population would naturally choose this mound for its strength and its commercial advantages. Bethlehem projects eastward into the Judean desert, picking up secondary roads that cross it. It had immediate access to the desert's herding industry, as well as Bedouin commerce. On its eastern flank, its people cultivated grain and olives. On the west they had vineyards and orchards.
Scripture taken from the NEW AMERICAN STANDARD BIBLE(r), (c) Copyright 1960, 1962, 1963, 1968, 1971, 1972, 1973, 1975, 1977, 1995 by The Lockman Foundation. (www.Lockman.org)