The US says, the core of al Qaeda leadership, based in Pakistan, might have been crippled but it still retains the intent and capabilities to strike the country. In a speech at the Harvard Law School, Cambridge, Massachusetts, Assistant to the US President for Homeland Security and Counter terrorism John Brennan said that al Qaeda's affiliates in places like Pakistan, Yemen, and countries throughout Africa carry out its murderous agenda.He said, in the face of this ongoing and evolving threat, the Obama Administration has worked to establish a counter terrorism framework that has been effective in enhancing security. Brennan said the administration addresses each threat in a way that best serves the national security interests, including building partnerships with countries around the world.