This isn't about whether the Iranians are pro-Pakistan or not, it is about the fact that a US military escalation with Iran has the potential for severe blowback on Pakistan given we're an Iranian neighbor. The Iranians are very likely to use their proxies in Pakistan (and elsewhere in the region) to attack US interests. And even if attacks on US interests in Pakistan are traced back to Iran, the negative fall out on Pakistan will still be significant and reverse all the gains Pakistan has made in terms of attracting tourists and foreign investors. Any escalation in conflict will likely also impact oil prices significantly which will also in turn have a significant negative impact on a Pakistani economy still struggling to balance itself.