The five-week war caused thousands of casualties on both sides and was witness to the largest tank battle in military history since World War II. The war started following Pak President Ayub Khan's ambitious Operation Gibraltar, which was designed to infiltrate forces into Kashmir to precipitate an insurgency against India.
The trigger was the attack in Kutch, Gujarat, which soon became a full-fledged war in which the Indian troops almost reached Lahore. A ceasefire was brokered by the then Soviet Union, and both troops had to retreat to another ceasefire line.