The 1965 second Indo-Pakistan War was an armed conflict between Pakistan and India  from August to September 1965. The conflict began following Pakistan’s infiltration of forces into Jammu and Kashmir to precipitate an insurgency against Indian rule. The seventeen-week war caused thousands of casualties on both sides and held the largest engagement of armored vehicles and tanks since World War II.

Source: https://en.wikipedia.org/wiki/Indo-Pakistani_war_of_1965