The Disbelievers are Allies of Each Other; the Muslims are not their Allies

After Allah mentioned that the believers are the supporters of one another, He severed all ties of support between them and the disbelievers. In his Mustadrak, Al-Hakim recorded that Usamah said that the Prophet said,

«لَا يَتَوَارَثُ أَهْلُ مِلَّتَيْنِ، وَلَا يَرِثُ مُسْلِمٌ كَافِرًا، وَلَا كَافِرٌ مُسْلِمًا»

Said in the second verse (73) وَالَّذِينَ كَفَرُ‌وا بَعْضُهُمْ أَوْلِيَاءُ بَعْضٍ (And those who disbelieve are friends to each other). The word: وَلِی (waliyy) used here, as stated earlier, carries a general sense included wherein is inheritance as well as the guardianship and patronage of affairs. Therefore, from this verse, we learn that disbelievers shall be considered inheritors to each other and the very law of the distribution of inheritance which is in force in their own religion shall be implemented as far as matters of their inheritance are concerned. In addition to that, the guardian وَلِی (waliyy) responsible for the upbringing of their orphaned children and for the marriage of their girls shall be from among them. In a nutshell, it means that, in family matters, the religious law of non-Muslims themselves shall stand duly protected in an Islamic state.

At the end of the verse, it was said إِلَّا تَفْعَلُوهُ تَكُن فِتْنَةٌ فِي الْأَرْ‌ضِ وَفَسَادٌ كَبِيرٌ‌ (And if you will not do so, there shall be disorder on the earth, and a great corruption - 73).