PRINCETON, N.J. — In 2000, the world's leaders met in New York and issued a ringing Millennium Declaration, promising to halve the proportion of people suffering from extreme poverty and hunger by 2015.

They also pledged to halve the proportion of people without safe drinking water and sanitation; move toward universal and full primary schooling for children everywhere — girls as well as boys; reduce child mortality by two-thirds and maternal mortality by three-quarters; and combat HIV/AIDS, malaria and other major diseases. These pledges, reformulated as specific, measurable targets, became the Millennium Development Goals (MDGs).

Last month, 10 years on from that meeting, world leaders returned to New York for a United Nations summit that adopted a document called Keeping the Promise, which reaffirmed the commitment to meeting the goals by 2015. The U.N. press release called the document a "global action plan" to achieve the MDGs, but it is more an expression of aspirations than a plan. What chance do we really have of keeping the promises made in 2000?