Muhaqqiq Karakī travelled to Iran twice. One time during the time of Shāh Ismā’īl and the other during the time of Shāh Tahmasp, and during these visits he stayed for some time. I think during that time he also visited Herāt (in Afghanistan). An incident happened that caused Karakī to scold and disassociate from Shāh Ismā’īl. The grandson of Mullā Sa’d Taftāzānī, the author of the book al-Mutawwal, was a respectable scholar and the representative of the Sunnīs in Herat.
After Shāh Ismā’īl conquered Herāt, he ordered the Sunnī scholars and the Shi’ī scholars to have a debate in his presence. One of the debates that took place in the Shāh’s presence was with the grandson of Taftāzānī who was a very dogmatic person and showed no respect for the opposing party. Shāh Ismā’īl ordered for him to be killed. A short while later Karakī visited Herāt and became aware of what had transpired. He said to the Shāh: “What you did wasn’t right. Using intellectual proofs and textual evidence I could have persuaded him, and if he became Shi’ī the whole of Herāt would have become Shi’ī too. (With your action) you have now prevented the spread of religion.”
Source: Jur’eh’ī az Daryā by Sayyid Shubayri Zanjāni, v. 2, p. 311