Which world leader has the biggest headache caused by the death of Osama bin-Laden? That would have to be General Ashfaq Kayani, commander of Pakistan's military and, as such, the most powerful man in the country where al-Qaeda's fugitive leader had been hiding in plain sight. Kayani now faces an escalation of the already crisis-level tensions in the relationship with his military's main benefactor, the United States, whose billions of dollars in aid to the Pakistani military is intended, first and foremost, to buy cooperation against al-Qaeda.