Beyond its massive territorial possessions in Iraq and Syria, ISIS is establishing affiliates across the world, recruiting wherever they can find potential followers. One of the biggest potential recruiting pools is Pakistan.
ISIS has found several fertile environments around the world for recruitment, and several where territory was more readily seized. In Pakistan, seizing territory outright is likely to be far more difficult, with myriad Islamist factions already in place in the tribal areas, and a powerful military.
Karachi, one of the biggest cities on the planet, seems to be the center of ISIS recruitment in Pakistan, reflecting the different approach ISIS has to take in Pakistan than in, say, Libya. There’s no realistic chance of ISIS ever taking over Karachi, but it’s a huge city with a lot of disaffected people in it, perfect recruitment targets.
ISIS has also established a fast growing affiliate in neighboring Afghanistan, and with that affiliate based around Jalalabad, on the Pakistan border, they are finding themselves quickly at odds with not only the governments there, but with rival militants who don’t want the competition.