In a decisive diplomatic escalation following the deadly terrorist attack in Karachi, Pakistan has formally summoned the Afghan Charge d'Affaires in Islamabad and simultaneously delivered a matching demarche to Afghan authorities in Kabul through Ambassador Nizamani. The démarches are backed by verified evidence, including interrogations of a detained Afghan national, establishing conclusive proof that Afghan territory and its nationals were instrumental in planning and executing the attack. This development marks a critical juncture in Pakistan-Afghanistan relations, where Islamabad is moving beyond verbal protests to demand accountability and tangible action from Kabul against militant elements exploiting Afghan soil. In my opinion, this move is both necessary and overdue—Pakistan has repeatedly faced cross-border terrorism, and presenting concrete evidence shifts the burden of proof onto the Afghan government to either cooperate or face international isolation. The reliance on forensic and intelligence data strengthens Pakistan's diplomatic hand, but the real test lies in whether Afghanistan's Taliban-led administration will act against these elements or continue to deny complicity. The Karachi attack underscores the urgent need for regional counterterrorism coordination, and Pakistan's firm stance sends a clear message: impunity for such attacks will no longer be tolerated.