According to my observation, the presence of US in Afghanistan is a blessing for India in terms of her economic, political and strategic interests. The reason is that the US has been supporting and sponsoring India through different means to support her in Afghanistan (Civilian nuclear deal is an example) in order to post a diplomatic threat to Pakistan and India has been cashing this. Indian policies have been driven by bilateralism, in the cold war era, she enjoyed the support of both sides (capitalists as well as Communists). So owing to the historical facts one can infer that the returning back of US would pose a serious problem for India and might damage her interets seriously because Pakistan would again regain her lost influence at the expense of India. About implications for Pakistan, everyone knows that what would be the scenario.

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"Success is not final, failure is not fatal; it is the courage to continue that counts" (Winston Churchill)