U.S. Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov are meeting Tuesday in Paris, hoping to find a way to begin reversing a yearlong spike in tensions stemming from Ukraine's civil war.

The formula for improved relations is simple: an easing of Western sanctions in exchange for an end to Russia's destabilization of its neighbor. Getting there has been far from easy.

There are some causes for optimism, however. Most Russian troops appear to have left the scene of the fiercest fighting between Ukrainian government forces and separatist rebels, according to Ukrainian military officials. And with economic penalties beginning to bite in Russia, President Vladimir Putin is heading to Milan, Italy, for talks with Ukraine's president and European Union leaders later this week.