Verse 90

إِلَّا ٱلَّذِينَ يَصِلُونَ إِلَىٰ قَوْمٍۭ بَيْنَكُمْ وَبَيْنَهُم مِّيثَـٰقٌ أَوْ جَآءُوكُمْ حَصِرَتْ صُدُورُهُمْ أَن يُقَـٰتِلُوكُمْ أَوْ يُقَـٰتِلُوا۟ قَوْمَهُمْ وَلَوْ شَآءَ ٱللَّهُ لَسَلَّطَهُمْ عَلَيْكُمْ فَلَقَـٰتَلُوكُمْ فَإِنِ ٱعْتَزَلُوكُمْ فَلَمْ يُقَـٰتِلُوكُمْ وَأَلْقَوْا۟ إِلَيْكُمُ ٱلسَّلَمَ فَمَا جَعَلَ ٱللَّهُ لَكُمْ عَلَيْهِمْ سَبِيلًا

Exempted are those who have joined people whom you have a treaty with them, or those who come and lack the courage to fight you or to fight their own people. And had God willed He could have had them mobilize against you then they would have fought you. Therefore, if they leave you alone and do not fight you and offer you peace, then God does not allow you to confront them in any way.