[JURIST] Russian President Vladimir Putin [official website] and representatives of Crimea signed a treaty [speech] on Tuesday that incorporates Crimea, currently a part of Ukraine, into the Russian Federation. The agreement comes after a referendum [JURIST report] in which more than 95 percent of Crimean voters, largely ethnic Russians, elected to secede from Ukraine and request to join Russia. The US, EU and Ukraine have challenged the legitimacy of the referendum and refuse to recognize Crimea as an independent nation or as a part of Russia. The Crimean Peninsula, historically controlled by the Russian Empire and the Soviet Union, has been under control of pro-Russian forces since the ouster [JURIST report] of former Ukrainian President Viktor Yanukovich in late February.

The ongoing conflict [BBC timeline] in Ukraine is being called the “biggest crisis between Russia and the West since the Cold War.” US President Barack Obama [official website] in March condemned [JURIST report] Russia’s military intervention in the region as a violation of international law. Ukraine’s interim government in February requested an international arrest warrant [JURIST report] for ousted former president Yanukovich, implicating him in the “mass murder” of civilians during protests in Kiev. Earlier that month US Vice President Joe Biden [official profile] threatened targeted sanctions [JURIST report] against Ukrainian officials responsible for violence against civilian protesters. UN High Commissioner for Human Rights Navi Pillay [official website] called for a peaceful resolution [JURIST report] to the crisis in Ukraine in February.