The phrase ‘leaders of disbelief’ referred to the Quraysh who, because of their position of leadership in Arabia, led the movement of opposition against Islam. This was the first prominent group to oppose the movement of Islam, wherever it arose. Its members, feeling that its superior position was being adversely affected by the pure call of Truth, were clever enough to pick out trivial points in the divine call in order to discredit it and they had the resources to thrust the Muslims into different types of difficulties in order to discourage them. 'They have no regard for their pledged word' is a very meaningful sentence. The pledges and treaties of those who oppose Islam out of enmity and obstinacy are uncertain and unreliable. The attitude is that of constant irritation with their opponent. There is no consistency in them. Even if they execute an agreement they are unable to uphold and maintain it for long due to the vagaries of their temperament. It does not take long for them to be overcome by their negative feelings and break their pledges.