Advocates attending an Amnesty International \"Shadow Summit\" in Chicago Sunday urged NATO leaders to consider the future of Afghan women. During the \"Shadow Summit for Afghan Women,\" Amnesty International released an open letter to President Barack Obama and Afghan President Hamid Karzai, criticizing them for excluding women from discussions about the future of Afghanistan. \"In this climate, we are alarmed that inadequate attention is being paid to women\'s rights and participation in peace talks with the Taliban,\" the letter said. \"Women must be empowered in the educational, economic and political life of Afghanistan or the country will fail to achieve a stable and prosperous future after a decade of effort to secure and rebuild the country.\" The letter suggests guidelines for the leaders to use during talks to represent Afghan women better. Amnesty International reports the 46 signers of the letter include Oscar-winning actress Meryl Streep, former Secretary of State Madeline Albright, retired Supreme Court Justice Sandra Day O\'Connor, feminist icon Gloria Steinem as well as Khaled Hosseini, author of \"The Kite Runner.\" The Afghanistan-focused NATO summit in Chicago convened its second day Sunday while protesters clashed with police in downtown Chicago. NPR reported Obama warned Karzai of the hard road ahead. \"We still have a lot of work to do and there will be great challenges ahead,\" he said. \"The loss of life continues in Afghanistan and there will be hard days ahead.\"