The Musalman invasion of the Brahmaputra valley was repeated on several occasions during the next five centuries of Muslim rule over north India, but… - Ram Gopal

Dr. Misra observes: “Prithviraja could have now easily consummated his victory by chasing and annihilating his routed enemy. But, instead, he allowed the defeated Muslim army to return unmolested. This magnanimity, though in accord with the humane dictums of the Hindu Shastras, was completely unsuitable against a ruthless enemy who recognised no moral or ideological scruples in the attainment of victory. The Hindus lacked the capacity to comprehend the real nature of their ruthless adversaries and the new tactics needed to encounter their challenge to Indian independence.”

Beginning with the first Arab expedition against Thana near Bombay in A.D. 636 the Muslims only succeeded in establishing the Delhi Sultanate in AD 1206, that is, after prolonged and relentless efforts lasting as many as 570 years. The magnitude of the resistance offered by Indians can be easily comprehended if we remember that the duration of the effective Muslim rule over northern India, not to speak of the whole of India which was much less, if ever, lasted only 500 years (upto the death of Aurangzeb in AD 1707). ( p.101.)

The Arabs and the Turks, on the other hand, knew no rules and waged a grim and ruthless struggle to destroy their enemies. Feints and sudden attacks, manoeuvering under the cover of darkness and pretending defeat and flights, keeping a large reserve to be used only at critical moments - all these took the Indians by surprise and crippled their fighting capacity. The Indians never tried to take advantage of their enemy’s weakness and perhaps considered it unchivalrous to do so. Such magnanimity on the part of Indian kings… was a sure invitation to disaster against a ruthless foe who recognised no moral or ideological scruples in the pursuit of victory.”