Hamid Karzai was sworn in Tuesday as Afghanistan's first popularly elected president, opening a new chapter for the impoverished country while warning that the wars against terrorism and drugs will require sustained international help. A smiling Karzai, wearing a traditional green robe and a black lambskin hat, received a standing ovation on his arrival. U.S. Vice President Dick Cheney, the highest-ranking American official to visit Afghanistan since the fall of the Taliban in 2001, was among the 600 guests, including 150 foreign dignitaries. After the Afghan national anthem, sung by a children's choir, reverberated around a restored hall of the war-damaged former royal palace, Karzai placed his right hand on a copy of the Quran, and repeated an oath of allegiance read to him by Afghanistan's chief justice, Fazl Hadi Shinwari. "I swear to obey and safeguard the provisions of the sacred religion of Islam, to observe the constitution and other laws of Afghanistan and supervise their implementation," Karzai said, "and with the assistance of God and the support of the nation, to make great and sincere efforts for the happiness and progress of the people of Afghanistan." Karzai then swore in his two deputies, Ahmad Zia Massood and Karim Khalili, members of the country's two largest ethnic minorities. --More 1048 Local Time 0748 GMT