For more than a decade, the very idea of multilateralism often seemed to be on life support — damaged by the Iraq invasion and its messy aftermath, buffeted by the global economic crisis and bruised by the difficulty of coming to agreement on critical trade and climate issues in Doha and Rio, respectively. Now, the world’s attention is riveted on whether the United States and Russia’s agreement to avert the immediate crisis triggered by the use of chemical weapons in Syria can be effectively overseen by the United Nations Security Council.

But a more consequential test for multilateral cooperation is looming, one that will shape the world for decades to come. That is whether, by 2015, the international community — from the halls of U.N. headquarters to the poorest corners of the globe — can identify our shared challenges and collectively act to solve them.

2015 marks the deadline for important negotiations on development, climate change, finance and trade. And the jury is still out on whether the world’s nations can reach agreement in any of these areas — much less all of them. Given the enormous stakes involved, all the U.N. member states must seize this opportunity to revive global partnership.

One of the last great examples of international cooperation could provide the spark to get multilateralism back on track by the 2015 deadline. In 2000, 189 U.N. members agreed to the Millennium Development Goals, an ambitious agenda that included halving the proportion of people living on less than $1 a day, ensuring boys and girls have universal access to primary school and beginning to reverse the spread of HIV/AIDS.

While the Millennium framework was not perfect, and results have been uneven, the goals have largely succeeded in uniting the world behind a common agenda. As a result — and despite the global financial crisis — the drop in extreme poverty over the last decade has been the steepest in human history.