Even when Pakistan was member of US sponsored military alliances like CENTO, SEATO, they managed to get massive military aids from China also. What was the secret of this?
As far as Pakistan is concerned, China is very close to them and want to give military aid because aim of China is to create problems for India. China can never be trusted. They have occupied vast areas of India and are intent on occupying more. They are just looking for excuses. China has constructed roads through Pakistan occupied Kashmir linking Pakistan and will support Pakistan in case of future wars of Pakistan with India.
US used China as a buffer against USSR. For example, the US CIA and China supported Khmer Rouge whereas the Soviets and most of the world sided w/ Vietnam. The US supported China's invasion of VIetnam in 1979 as an attack against a Soviet sponsored state.
Pak got benefitted MASSIVELY by the Sino-Soviet split because US was using China against USSR. In DRA Afghanistan, the US and Pak and China all supported Talibans against DRA AFghanistan, USSR and against us in form of insurgency.
Initially USA and China used to use Pakistan as communication medium in those days.
But now it has become compulsion for them to meet Pakistan's hunger.