The roots of the current standoff in Crimea go back a few days, and weeks, and years, and centuries. Here's a look at how the situation evolved; my 486 words, not counting captions, start now:
What has happened in the past few days
Thousands of Russian troops have entered Crimea, a peninsular portion of Ukraine with strong ties to Russia and which is home to Russia’s Black Sea fleet. Ukraine’s interim government has called this an invasion, and U.S. and European officials have warned Russia that it will face consequences if it doesn’t withdraw. Russian President Vladimir Putin said that the troops aren’t Russian but that he has the right to send in troops.