Why are North Korean troops in Russia?

The United States confirms it has evidence that North Korean troops are in Russia. Questions remain as to whether the North Korean soldiers are being trained to support Russian forces on the battlefield in Ukraine. South Korean officials worry the Kremlin may reward the North by giving it sophisticated weapons technology targeting South Korea. We speak with Thomas Graham, a distinguished fellow at the Council on Foreign Relations and former special assistant to the president and senior director for Russia on the National Security Council staff joins us for analysis into what it could mean for Europe and the Indo-Pacific.