American scholar Roger C. Algase, in his thesis comparing the laws of Warfare in Shariah with modern international law, states that the laws of Shariah:
“strikes a balance between military necessity and respect for human life in a manner which gives a higher priority to saving the lives of non-combatants than does modern international law…the Islamic law dealing with the conduct of war is in a better position than modern theory to develop an effective approach to the problems involved in the law of war crimes…”
“The growth of the legal literature in the early centuries of Islam which attempted to anticipate every possible situation which could arise in any area of human conduct leaves perhaps less room for uncertainty as to what the law is than the modern case method…
[Roger Algase, ‘Protection of Civilian Lives in Warfare: A Comparison Between Islamic Law and Modern International Law Concerning the Conduct of Hostilities’]
Islamic Laws VS Geneva Convention with Regards to Prisoners of War:
Troy S. Thomas concludes in his thesis on the Laws of Shariah with regards to prisoners of war that:
“Finally, it [i.e. the thesis] argues that the (Islamic) laws governing the treatment of POWs are at least as equally benevolent as the Geneva Convention and are in some specific cases broader in scope. Ultimately, they carry a more convincing sanction.”
[Jihad's Captives: Prisoners of War in Islam by Troy S. Thomas]
Islamic Laws of Warfare vs European International Law:
German Scholar Hans Kruse states in his seminal thesis on Islamic International Law that:
“the positive international law of Europe had more than eight centuries later not yet reached the high degree of humanitarianization with which the Islamic law of war was imbued.”
[Hans Kruse in his ‘Die Institution des Djihâd im islamischen Völkerrecht’. English Translation of Title: The Institution of Jihad in Islamic International Law]
How the Early Muslims Treated the Conquered Lands:
The famous French political scientist, historian and thinker, Gustave Le Bon, states in his detailed study of the conquests of the early Muslims:
“...history has never known a merciful and a just conqueror as the Arabs…Few are the nations that excelled the Arabs in civility….The conduct of the Commander of the Believers, ‘Umar ibn al-Khattâb, in Jerusalem (Bayt al-Maqdis) proves how kindly the Arab conquerors dealt with the conquered peoples, the opposite of what was done by the Crusaders in Jerusalem many centuries later…”
“The forbearance and toleration that characterized the Arab conquerors, of which historians were ignorant, seemed to explain to what extent they were able to expand their conquests… They used to show mercy to the weak, be kind towards the conquered and abide by the conditions they imposed upon themselves, to the end of those good traits… whichever region they invaded, if Syria or Spain, they treated the people with utmost gentlesness by leaving them their laws, their institutions and their religion…. Never before had the world known conquerors with such tolerance or with such gentle a religion.”
[Gustave Le Bon in his French work ‘La Civilisation des Arabes’ (The Civilization of the Arabs)]
Did the Muslims Forcibly Convert People?
The English historian, Sir Thomas Walker Arnold, mentions in his detailed study of the early conquests of the very first generations of Muslims:
“Of forced conversion or anything like persecution in the early days of the Arab conquest, we hear nothing. Indeed, it was probably in a great measure their tolerant attitude towards the Christian religion that facilitated their rapid acquisition of the country….
"Had the caliphs chosen to adopt either course of action [i.e. extermination or forced conversions], they might have swept away Christianity as easily as Ferdinand and Isabella drove Islam out of Spain, or Louis XIV made Protestantism penal in France or as the Jews were kept out of England for 350 years … the very survival of these churches to the present day is a strong proof of the generally tolerant attitude of the Mohammedan governments towards them…”
[The Spread of Islam in the World]