WASHINGTON – The Russian Federation on Saturday approved the armed invasion of Ukraine, prompting alarm and condemnation from governments worldwide over the violation of a nation’s sovereignty, a people’s rights to self-governance and the stability of Eastern Europe.After vowing to respect Ukraine’s independence through emissaries in Western capitals, Russian President Vladimir Putin requested permission from the Russian parliament to deploy military forces in the Crimea region on Saturday. The request was swiftly granted.Putin’s reversal came a day after he ordered more than 150,000 Russian troops to go on alert near the Ukrainian border, along with hundreds of ships and aircraft.Ukraine responded by putting its forces on full combat alert, warning of war.“Military intervention would be the beginning of war and the end of any relations between Ukraine and Russia,” Prime Minister Arseny Yatseniuk said on Saturday, standing next to acting Ukrainian President Oleksander Turchinov.Ukrainian military officials accused Russia of sending two anti-submarine warships to its coast, in violation of a pact between the two nations.Morale of the Ukrainian military is “high,” they claimed, motivated by what they characterized as Russian aggression.Russian action over the weekend marked a dramatic escalation in the political conflict that has challenged Ukraine for over four months.The nation of more than 40 million people – divided between a Russian past and its European aspirations – witnessed a political uprising last week that turned deadly when its pro-Russian president, Viktor Yanukovitch, ordered police to fire on anti-government protesters.More than 80 Ukrainians were killed, aggravating the protests and ultimately forcing Yanukovitch to flee Kiev, first to Crimea and then to Russia. Ukraine’s parliament voted him unfit for office and is forming a new government, with elections scheduled for May.A likely contender for the presidency in those elections said on Saturday that he favored the mobilization of Ukraine’s military in response to Russian movements.Thousands of armed men – of undeclared allegiances, but understood to be of Russian descent or hired militiamen – were already on the ground in Crimea on Friday, laying the groundwork for invasion, taking over government buildings, television and radio stations, and severing key lines of communication with Kiev.The Crimea region was once a part of Russia, and its residents still speak the language.Yet, despite their steeped cultural ties to Russia, a 1994 agreement between the two nations binds Moscow not to intervene in Ukrainian affairs and to respect its territorial integrity.Russian Foreign Minister Sergei Lavrov insisted to his American counterpart, US Secretary of State John Kerry, that all international treaties would be respected. But American intelligence agencies monitored troop movements over the weekend that indicated a larger operation might be in the offing.That prompted US President Barack Obama to deliver remarks on the crisis from the White House on Friday afternoon.“Any violation of Ukraine’s sovereignty and territorial integrity would be deeply destabilizing, which is not in the interest of Ukraine, Russia or Europe,” Obama said. “It would be a clear violation of Russia’s commitment to respect the independence and sovereignty and borders of Ukraine, and of international laws.”Putin’s request for authorization of the use of force came just hours after the US president’s warning. A meeting of the principals on the US National Security Council – Kerry, Defense Secretary Chuck Hagel, Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey, and CIA chief John Brennan – were seen meeting at the White House on Saturday.Full meetings of the principals are rare, and were last seen during the crisis with Syria over the use of chemical weapons in that country last August.Kerry spoke with Turchinov by phone on Saturday, pledging vague US support.Obama conducted a 90-minute phone conversation with Putin Saturday afternoon, during which Obama expressed his deep concern over Russia's "clear violation of Ukrainian sovereignty and territorial integrity," according to a statement by the White House Press Secretary's Office.The White House sees Russia's actions as a "breach of international law, including their actions under the UN Charter," it said.Obama also warned Putin that continued violations of international law would "negatively impact Russia's standing in the international community," calling on Russia to de-escalate tensions and withdraw its forces.British Foreign Secretary William Hague characterized Russia’s move as an “act of aggression” against Ukraine and a “potentially grave threat” to the country’s sovereignty.The US and its allies have little leverage over Russia in their efforts to stop an invasion.Ukraine is not a member of NATO – an organization founded to prevent Soviet aggression in Europe – and Russia retains a permanent seat on the United Nations Security Council, making any action through that body a nonstarter.US officials said they are monitoring the situation closely, only threatening to pull out of the G8 summit planned for June 4-5 in Sochi, Russia, should the Kremlin move forward with an invasion.Secretary-General Ban Ki-moon called “for the full respect for and preservation of the independence, sovereignty and territorial integrity of Ukraine,” the UN chief’s spokesman said, adding that Ban is “gravely concerned about the deterioration of the situation.”EU high representative for foreign affairs Catherine Ashton called on Moscow to solve its disagreements with Ukraine through “peaceful means,” while NATO chief Anders Rasmussen wrote on Twitter that Western allies saw an “urgent need” for a deescalation of the conflict.