A declassified US State Department letter that confirms the existence of hundreds of "infiltrators" in the Indian-administered part of the disputed Kashmir region
. Dated during the events running up to the 1965 war.
Since the Partition of British India in 1947, Pakistan and India remained in contention over several issues. Although the Kashmir conflict was the predominant issue dividing the nations, other border disputes existed, most notably over the Rann of Kutch, a barren region in the Indian state of Gujarat. The issue first arose in 1956 which ended with India regaining control over the disputed area. Pakistani patrols began patrolling in territory controlled by India in January 1965, which was followed by attacks by both countries on each other's posts on 8 April 1965. Initially involving border police from both nations, the disputed area soon witnessed intermittent skirmishes between the countries' armed forces. In June 1965, British Prime Minister Harold Wilson successfully persuaded both countries to end hostilities and set up a tribunal to resolve the dispute. The verdict, which came later in 1968, saw Pakistan awarded 350 square miles (910 km2) of the Rann of Kutch, as against its original claim of 3,500 square miles (9,100 km2).
After its success in the Rann of Kutch, Pakistan, under the leadership of General Ayub Khan, believed the Indian Army would be unable to defend itself against a quick military campaign in the disputed territory of Kashmir as the Indian military had suffered a loss to China in 1962 in the Sino-Indian War. Pakistan believed that the population of Kashmir was generally discontented with Indian rule and that a resistance movement could be ignited by a few infiltrating saboteurs. Pakistan attempted to ignite the resistance movement by means of a covert infiltration, codenamed Operation Gibraltar. The Pakistani infiltrators were soon discovered, however, their presence reported by local Kashmiris, and the operation ended unsuccessfully.