Altaf Hussain wants army to come into the streets of Karachi, so that urban terrorists of MQM can draw the army into streets and turn Karachi into a urban battlefield like Syrian and Iraqis cities have become..
This is the modern nature of war -- fight in the mega cities to decimate the city and the people ! They use ISIS, TTP, BLA, MQM, FSA type gangs -- various names, similar objectives !
Pak army is operating all over the country and have stabalzied the country a lot but Karachi remains a serious threat. Only a Martial Law and most ruthless hunting of MQM, PPP and other terror gangs would clean Karachi. If these corrupt rascals remain in power, then bringing in army would mean a disastrous civil war.... That is why army is reluctant.. But sooner or later, this will have to be done..