On Tuesday, Secretary of State John Kerry arrived in Kiev—$1 billion in guaranteed loans for Ukraine in tow—as Russian President Putin backtracked somewhat, saying military force would be used only as a "last resort," though he maintained the right to use "all options" in the crisis. Meanwhile, the Crimean prime minister told reporters that the majority of Ukrainian troops in Crimea have either surrendered or pledged allegiance to his government.

In his speech on Tuesday, Putin called the ousting of former Ukrainian President Viktor F. Yanukovych an "unconstitutional coup" necessitating Russia's intervention, which he described as "legitimate and within the framework of international law," to maintain order in eastern Ukraine and Crimea.

"We realized what was the major concern for the Ukrainians, the Russian-speaking people who reside on the southern and eastern regions of Ukraine, this is concern about lawlessness," Mr. Putin said, according to Reuters. "When they ask us for help – and we do have an official request from the president – we reserve the right to defend these people and we believe this is legitimate."

Putin also said all "threats [from the U.S. and the E.U] against Russia are counterproductive and harmful."

More than 150,000 Russian troops performing readiness tests near the Ukraine border returned to their bases on Tuesday as previously scheduled, though it's not clear if the decision was the result of international pressure.

Meanwhile, Prime Minister Sergei Aksyonov told reporters that most of the Ukrainian military had either surrendered or defected to his pro-Russian government and that "there is no safety threat to human life in Crimea." Aksyonov's claims contradicted reports that Russian troops in Crimea fired warning shots from a seized Crimean airfield at about 300 Ukrainian soldiers who'd gathered outside the base.

Last but probably not least: John Kerry arrived in Kiev on Tuesday to show his support for Ukraine's fledgling government, promising an immediate $1 billion in loan guarantees as well American assistance for more technical issues, like fighting corruption and training election monitors.

[Image via AP]