An Nisa’ Ayah 101
وَإِذَا ضَرَبْتُمْ فِى ٱلْأَرْضِ فَلَيْسَ عَلَيْكُمْ جُنَاحٌ أَن تَقْصُرُواْ مِنَ ٱلصَّلَوٲةِ إِنْ خِفْتُمْ أَن يَفْتِنَكُمُ ٱلَّذِينَ كَفَرُوٓاْۚ إِنَّ ٱلْكَـٰفِرِينَ كَانُواْ لَكُمْ عَدُوًّا مُّبِينًا ١٠١
When you travel through the land, it is permissible for you to shorten the prayer—?especially? if you fear an attack by the disbelievers. Indeed, the disbelievers are your sworn enemies.