Blame Nawaz
Nobody but nobody doubted where Nawaz stood on India. The only difference opinion-wise lay in whether he was viewed sympathetically or somewhat derisively for still, in a third stint, being unable to wrest any space from the boys. So Nawaz had two options: either split the difference between Modi and the boys in Ufa or wait a few months more and let the outside pressure build on Modi. He chose to be greedy. Or hasty. Or, sadly, just plain stupid.
You can see what he was going for — a commitment to get Modi in Islamabad next year for Saarc. You can see how a Modi visit would be a triumph for Nawaz. You can also see why Nawaz is such a bad foreign minister.