It was timely for the Prime Minister of Pakistan to visit China last week (see article here) as an alliance with a partner of this kind potentially gives Pakistan extra “scale” or “weight” in its discussions with the US, and these are recognised sources of bargaining power.
However, on closer scrutiny this development probably makes little difference to US/Pakistan relations. The Pakistan government has “security” negotiating needs with the US – fulfilled by large supplies of cash and other resources. It also has a constant domestic negotiation going on with its own radicalised Islamic population where it also has “security” needs – hence its ambivalent attitude to the war on terror.
China has an interest in friendly relations with Pakistan, but it is unlikely to want to supplant the US as a major supplier of cash and other resources. Equally, China, with a large Muslim population of its own which it wants to control, is unlikely to be any more in favour of Pakistan’s semi-tolerant attitude to extremists than the US is.
If, as a result of this, the US does not feel that there is any real threat that Pakistan could ever substitute China for its relationship with the US in its international dealings, then the US is unlikely to feel too anxious or threatened about a one-off visit by the Pakistan Prime Minister to China.