As countries prepare to sign the landmark Paris climate accord, the work to reduce global carbon emissions is only beginning, says CFR’s Michael Levi.

UN-mediated talks in Syria are jeopardized by disagreement over which opposition parties should participate, but a broader obstacle is whether a compromise over Bashar al-Assad’s future can be reache…

U.S. officials will have to consider the consequences of new sanctions as they weigh how to address Iran’s regional policies without derailing implementation of the nuclear accord, says expert Richar…

Outmatched by the Russian military, Ukrainian forces require more support from the Pentagon, including defensive weapons, says expert Steven Pifer.

A refugee crisis in northern Iraq’s Kurdish region is intensifying as winter approaches and the threat posed by ISIS forces shows no signs of abating, says journalist Jane Arraf.