No matter what the age, and no matter what country one might speak of, prisoners of war present a local problem for that country, and those prisoners are usually put to work (sometimes for a small wage) in some manner within the nation who captured them. This was no less true for ancient Israel. Certainly, most of these gentiles were uncooperative. Certainly they would have been held against their wills, and certainly they would have been made to work under armed guard. This is no less true for POWs in America during World War II than it was for ancient Israel under its kings (cf. 2Samuel 12:31; 1Kings 9:15, 20-22). Yet, though POWs were forced to serve their captors, who would conclude that this was slavery in the same vein as the slave institution that was practiced in early American history?
Nothing is said in the Bible that such forced servitude was permanent. Logic would claim otherwise, since ill treatment of POWs in Israel would interfere with friendly relations with the POWs native lands. Even if Israel was victorious, as she apparently was under David and Solomon in the Scriptures mentioned above, how could peace be maintained with its tributary neighbors, if the citizens of those lands were mistreated in Israel? The bottom line, according to the Law of Moses, is that the foreigner was not to be mistreated in Israel (Exodus 22:21).
Just because many foreigners within Israel were called servants doesn’t necessarily mean they were slaves in the sense the term is used in early American history. For example, the same word for servant (H5650 – ebed) is used for both Israelites and foreigners. The word can refer to soldiers who are leaders over hundreds or thousands of men (1Samuel 22:6-10). The word can also refer to royal counselors (1 Samuel 16:15) or administrators (2Kings 22:3) or ambassadors (2Samuel 10:2-3). It may even refer to a king who submits himself before a stronger king (2Kings 16:7). So, the term ebed or servant (H5650) doesn’t necessarily carry with it the same meaning we have understood for servant or salve in early American history.
Nevertheless, a foreigner living in Israel may not simply be the peaceful stranger who chose to live there or chose Israel in order to escape trouble and hardship in his own land. A foreigner might also be a dangerous or hostile individual—an enemy, living in Israel perhaps as a result of being a prisoner of war. Nearly all foreigners or strangers living in Israel were servants to some degree, because they could not own property. The Promised Land was promised to the descendants of Abraham, not gentiles. Therefore, there wasn’t much else a foreigner could do in Israel, if he chose to live there or was forced to do so through circumstance such as war. He either became a hired servant or a bond servant (i.e. one indebted to a creditor). Nevertheless, it may be of interest to note that the same servants who were first pressed into servitude (Leviticus 25:45), were sometimes able to acquire sufficient means to be free of creditors (masters) and have servants themselves (Leviticus 25:47)! How unfair could that be?
Prisoners of war were placed under guard and often put to work in civil projects, such as building or repairing cities, (1Kings 9:15, 20-21). Nevertheless, the treatment of the female prisoner under post-war conditions in Deuteronomy 21:10-14 implies that, after hostile actions ceased, those willing to return to their former lands were permitted to do so. More than likely they would still be responsible with their native land to send tribute to Israel (Deuteronomy 20:11), but the Scriptures do not indicate that God approved of and commanded Israel to enslave anyone, either of their own countrymen or of other nations. In fact, Sheshan, a descendant of Caleb, gave his daughter to his Egyptian servant, Jarha (1Chronicles 2:34-35). Egypt was Israel’s former enemy, for Pharaoh sought to destroy Israel or bring her back into bondage to Egypt.
 As I said HERE, this current theme about “making sense of the Old Testament God” is based upon the book: Is God a Moral Monster by Paul Copan. These are my thoughts about his book. He may or may not agree with the impression his book has made upon me, but I thoroughly enjoyed reading what Paul wrote and recommend his book to anyone who is looking for a good read concerning defending our faith.