The G20 summit comes amid tensions over trade, climate, and refugee policy and increased uncertainty over the U.S. commitment to multilateral institutions.

An escalating migration crisis is testing the European Union’s commitment to human rights and open borders.

The crisis has spiraled into conflict that has killed thousands and continues to feed tensions between Russia and Western powers over Moscow’s support for separatists.

The most recent crisis in Ukraine has invited closer scrutiny of the European Union’s approach to its Eastern neighbors.