What if the U.S. judges that however much it wants a containment perimeter around the USSR, Pakistan is more of a liability than an asset. Allying with Pakistan bilaterally, without a prior common South Asian defense agreement (between India and Pakistan) threatens to alienate larger India and the more forwardly positioned Afghanistan.
In building SEATO in 1954, the US decides to not seek or accept Pakistan as a member, figuring it is hardly near the Southeast Asia region (even with East Pakistan) and that India would be more important.
In building CENTO and the Baghdad Pact in 1955, the US decides that the Shah's Iran after '53 provides sufficient coverage of the southern USSR. Washington hopes to add Afghanistan to the alliance, but is not interested in Pakistan as a second-choice.
I suspect under the circumstances, without the US-Pakistan alliance, Pakistan is weaker in terms of armament. All other things being equal, I think Nehru would go through the 1950s and 1960s remaining committed to non-alignment. Afghanistan will probably stick to neutrality also, not wanting to alienate the USSR while having crappy relations with Pakistan, and not seeing a connection to the outside world just through the Shah's Iran alone as a safe bet.
I suspect US U-2 flights will base from Iran instead of Pakistan.
What is happening by the time we get to the mid-1960s?
Have the Pakistanis made an alliance with the USSR or PRC?
If not, would it be mainly because neither would be interested in being a partner with Pakistan, for the same reasons the US declined to ally?
If Pakistan allies with China earlier as a result, will that either cause a (more poorly armed) Pakistani attack on India during the 1962 Sino-Indian war. Or lead to an India de facto aligned with the US while still officially non-aligned?
Without a U.S. alliance and related US arms sales, would Pakistan have the confidence to attack India in 1965?
Would India do any major bullying against Pakistan between 55 and 65 if Pakistan lacks allies?