Military governed the country for more or less 40 years. What improvement did Karachi see in that period. The solution is not calling in army. The solution is to improve administration's capability.
Even Somali pirates would manage Karachi better than PPP/MQM cancer cells.
Seriously though, only solution is smaller provinces. Problem with places like Karachi, Multan, Pindi and Gawadar in future, is that they are not "owned" by the people ruling over them. Karachi's elected reps are powerless and corrupt. Make small provinces and transfer power. We have seen glimpses of its success under LG system of Mush.
کراچی میں بارش ہوئی اور نالوں کی صفائی کی وجہ سے سڑکوں پر پانی جمع نہیں ہوا پاک فوج نے وزیراعظم عمران خان کی ہدایت پر کام کیا تھا۔
look what common people saying about Pak Army and sindh anil kapoor is talking about constitution