Messervy quickly got enmeshed in the Pakistani efforts to forcibly acquire Kashmir (then an unaffiliated princely state). On 20 August, a letter signed by Messervy went out to all the brigade headquarters in northwest Pakistan, attaching plans for a certain Operation Gulmarg. According to the plan, 20 lashkars of Pashtun tribesmen were to be armed and trained in various brigade locations in northwest Pakistan for an armed invasion of Kashmir. The information leaked out, one of the letters having fallen into the hands of an Indian officer Major Onkar Singh Kalkat. Kalkat was put under house arrest, but he escaped and made his way to India. By the D-day of 22 October, when the attack was launched, Messervy was away in London, leaving General Douglas Gracey, the Chief of General Staff, as the Acting Commander-in-Chief