The kingdom was sometimes threatened by nomads; a letter sent to Yasmah-Adad informs him that 2000 Suteans conducted a raid against Qatna. Relations with Yamhad worsened during Išḫi-Addu's reign and the conflict evolved into border warfare; Qatna occupied the city of Parga in the region of Hamath for a while before Sumu-Epuh retook it. In the south, Išḫi-Addu faced a general rebellion; the alliance with Assyria was cemented by the marriage of Išḫi-Addu's daughter to Yasmah-Adad in . The following year, after petitions by Qatna, Shamshi-Adad sent an army to help Išḫi-Addu deal with the rebellion. The Assyrian troops avoided engaging Yamhad and did not participate in its war with Qatna, while Išḫi-Addu took up residence in Qadeš to oversee the suppression of the rebellion, which apparently was supported by Yamhad. After four years in the service of Qatna, Shamshi-Adad ordered his troops to return; this might have been connected to a peace treaty between Assyria and Yarim-Lim I, son of Sumu-Epuh. Išḫi-Addu, who in the past had declared that "even if Shamshi-Adad would conclude peace with Sumu-epuh, I will never make peace with Sumu-epuh, as long as I live!", was delivered a heavy blow, but Mari's sources are silent on how the king dealt with the situation, and by the time they resumed mentioning Qatna in , Išḫi-Addu was dead and succeeded by his son Amut-piʾel II.