US Secretary of State Hillary Clinton has said that the leadership of Pakistan and Afghanistan realize that the three countries have a common enemy, report said. We have a common threat, we have a common target and we have a common challenge, Hillary told the delegates at the introductory session of tripartite meeting of Pakistan, Afghanistan and U.S. commenced here Wednesday. President Asif Ali Zardari and Afghan President Hamid Karzai also flanked the top US diplomat. We welcome the leaders of Pakistan and Afghanistan who took the reins of their countries at a time they are facing crisis, Hillary told the gathering, adding that the three countries are fighting the enemies of democracy. She urged the need to chalk out a joint strategy and an agreement on joint anti-terror efforts among the three countries and vowed to extend all possible support by the U.S. to the two countries for the cause.