People gather in the Kyiv subway, using it as a bomb shelter in Kyiv, Ukraine, Friday, February 25, 2022. [AP Photo/Efrem Lukatsky]
Since Russia invaded Ukraine, the world has watched in disbelief as a nuclear and military power invaded a sovereign nation. Debate rages over whether the invasion was an expansionist move to reunite former imperial territories or to curb security threats arising from the prospect of Ukraine joining Nato.