Is non-state warfare allowed in Islam?

This Islamic principle is that there is no room for non-state warfare, which is what we generally call guerrilla war. A guerrilla war is fought by individuals and individual organizations, not by the State.

As a general principle, the Quran tells us that, even where an external attack is feared, the common man should not act independently, but should take the matter to the ruler, and then under his guidance take proper counter measures. (4:83).

The Hadith also states that ‘the ruler is a shield, fighting is done under him, and security is attained through him.’

This clearly shows that the decision to do battle and its planning are the tasks of an established government. The common man can play his role as need be under government orders, and not independently.