One could argue that white Americans conquering the territory of the present United States and exterminating the Indian tribes was reasonable because the American nation, consisting mainly of European immigrants, could not co-exist with the Indian nations because of different governments, concepts of land ownership, religious beliefs, etc. In order to ensure the survival and growth of the American nation, the original nations had to be expelled, through murder, forcible expulsion, or mutual agreement. Yet the acts of the American nation and of white Americans constituted theft and murder, even if the Indian tribes did not have a concept of individual ownership of land and natural resources and even if a tribe that white men encountered, for instance the Comanches in Texas, had conquered the previous inhabitants of the area and killed or dispossessed them prior to the arrival of the Spaniards and the Anglo-Americans. Most of the whites considered themselves Christians; American common law derived from its English ancestor, which in turn was partially rooted in Biblical precepts. Theft and murder are violations of the Fifth and Sixth Commandments, respectively. The actions of the white Americans and the colonial, Federal, and State governments were reasonable, as they ensured the nations survival, but they were also immoral.
By what standard would the actions of the Jews with respect to their conquest of Canaan have been reasonable? As with the white American vs. Indian conflict, the Jewish nation could not co-exist on the same territory with the Canaanites. The Ten Commandments had already been given to Moses at the time the Jews arrived in what is now modern Israel. Yet the same Lawgiver who gave them the Decalogue and the Law also commissioned them to do these acts. Is this a contradiction? A Christian assumes that God is perfect, and He must therefore be free of contradiction.
The Christian also assumes that Gods power is infinite. The Westminster Confession of Faith discusses the sovereignty of God in Chapter III, Article 1. "God from all eternity did, by the most wise and holy counsel of His own will, freely and unchangeably ordain whatsoever comes to pass: yet so, as thereby neither is God the author of sin, nor is violence offered to the will of the creatures, nor is the liberty or contingency of second causes [i.e., mans responsibility] taken away, but rather established." Not only is God perfectly just, He is entirely sovereign, in a sense no earthly king or state is, with perfect foreknowledge and the power to foreordain events. In other words, if the conquest of Canaan occurred, it was because God wanted it to happen.
Lets deal with the issue of Gods provision for justice. If God is perfect, then His justice must be perfect. The enforcement of justice is not pleasant upon the criminal, or at least should not be. The death penalty or long prison terms are harsh, yet are means of justice. Of what crimes were the Canaanites guilty? Genesis 18:16-19:29 tells the story of Sodom and Gomorrah, two cities in Canaan where gangs and swarms attacked people for fun. (Please note that God destroyed those cities for their wickedness.) Canaanite religion involved child sacrifice. It was a practice that increased the more their cities expanded. Unlike other ancient civilizations where such practices died out, the Canaanites perpetuated it, as evidenced by archeology. If the atheistic Communists were used as Gods instruments of justice on the neo-pagan Nazis in 1945, there is no reason to think that God would not have done so with the Jews and the Canaanites circa 1300 B.C. Imperfect, sinful men, Communists and Jews, are used to punish wicked men, Nazis and Canaanites, deserving of Gods wrath.
Beyond the issue of the motives of the Jews, we must ask what Gods motives were. If God is perfect, He must then have infinite power and moral perfection. If He had less than perfect attributes, then there could be another being that is greater than God, even if we do not know that being, just as the baseball accomplishments of Babe Ruth were surpassed by Hank Aaron, Roger Maris, Mark McGwire, etc., even if Aaron, Maris, and McGwire did not exist when Ruth was at the height of his career. If God is imperfect in either His character or His power, He cannot be God as the Christian conceives Him. Thus, we must view the actions and commands of God as being consistent with His perfect nature. The Bible attests to the perfection and infinite power of God in numerous passages. God therefore could not have been and were unreasonable in His command to the Israelites to take possession of Canaan and kill and dispossess the Canaanites.
One could argue that this position regarding the nature and character of God is dogmatic. Yet any philosophical system is based on some sort of axiom, including empiricism. As Gordon Clark, a 20th Century Calvinist philosopher put it: To say that statements are nonsense unless verifiable by sensation, is itself a statement that cannot be verified by sensation. Observation can never prove the reliability of observation. Since, therefore, every philosophy must have its first indemonstrable axiom, the secularists cannot deny the right of Christianity to choose its own axiom. (How Does Man Know God, by Gordon Clark, available on The Trinity Foundations Web site, www.trinityfoundation.org). Christians rely on first principles, but so do all others.
Granted, many of the attributes Christians see in God resemble those Muslims see in Allah. Evangelical Christians and traditional Muslims have a similar epistemology: reliance on a holy book inspired or written by God as foundational in understanding the nature of man and the universe. However, this similarity in epistemology does not mean similarity in worldview. The Marxists and the Objectivists also share a common epistemology of naturalism. Yet Marxists and Objectivists have worldviews that are quite opposite to one another. A similar argument could be made for Nazis and New Age adherents, both of which are rooted in polytheism and monism. Reliance on a holy book does not make the worldview of the evangelical Christian similar to that of the traditional Muslim, even if the mainstream media and culture lump both together as fundamentalism.
I agree that one should not judge either the Christian or the Muslim faith by the excesses of those who call themselves adherents. Yet we cannot isolate a nations culture from the worldview of the leadership and citizens of that nation. If the Islamic faith in former Yugoslavia was more tolerant than elsewhere, it is because they were influenced not only by Islam, but by the Christian faith of the region and their ancestors. (Bosnians and Albanians were members of one Christian sect or other prior to the Turkish conquest of southeastern Europe in the 15th Century. The Slavic and Albanian Muslims still celebrate some church-related feasts and drank wine, brandy, etc.) On the other hand, the Arabian Peninsula received little Christian influence, and the Muslim conquerors in the 7th and 8th Centuries ruthlessly wiped out the churches and Christian believers throughout the Middle East and North Africa. Thus, the sole significant influence in the Arab world is Islam. What are its results? As you stated, Arab culture is violent, oppressive, and exclusionary. My argument is that you cannot isolate a civilization from its philosophical moorings. There are individual deviants, like a John Muhammad, the man accused of the sniper deaths in the D.C. area or like a Paul Hill, the defrocked Presbyterian minister convicted of killing an abortionist. These deviants are not the measure by which you measure the effect of a religion on a society. Rather, it is that society itself.