Nine years ago, thousands upon thousands of Ukrainians turned out to protest rigged elections and demand democratic leadership, in what came to be called the Orange Revolution. Now they are out on the streets again. Kathy Lally, The Washington Post’s Moscow bureau chief, explains.

Why are they protesting?

Over the past few days, demonstrators have surged through the streets of the Ukrainian capital, Kiev, angry that their president, Viktor Yanukovych, had backed off on signing an agreement with the European Union on Friday that would have put the country, philosophically at least, in the European camp. Instead, he intends to improve relations with Russia. Ukrainians grew even more infuriated Saturday when police used force to disperse protesters. On Sunday, an estimated 300,000 or more demonstrators filled Kiev’s Independence Square, demanding that the president resign.

Why should the U.S. care?

Shades of the Cold War! Hillary Rodham Clinton put it this way: A year ago, when she was still secretary of state, Clinton said Russia was trying to ­“re-Sovietize” the area once ­occupied by the 15 republics that made up the Soviet Union. Russian President Vladimir Putin has already formed a Customs Union with two of the countries, Kazakhstan and Belarus. Armenia has promised to join. Now, he has his eye on more desirable Ukraine. At home, Putin enjoys casting the United States as public enemy No. 1, mostly to make himself look like the protector of the nation. That would be harder to pull off if Ukraine rejected his advances and took up with Europe, an old U.S. friend.

What’s in it for Ukraine?

The European Union offered an association agreement that would have given Ukraine loans and favorable trade relations with Europe, conditions providing long-term benefits but probably little short-term relief for an economy verging on bankruptcy. Russia reportedly offered immediate enticements, such as big loans and reduced gas prices, that would have delayed financial crisis but that also would have put off a much-needed revamp of the economy. Yanukovych, facing re-election in 2015, apparently went for the quick fix. But a younger generation, looking toward a future in Europe, disagreed.

Why fight over Ukraine?

The country has about 45 million people, not quite one-third the size of Russia. But it exerts a powerful hold on the Russian imagination and also has deep potential as a trade partner. The Russian nation grew out of a 9th-century Slavic stronghold known as Kievan Rus. Putin considers his neighbor to the west deeply tied to his country’s history and culture. Some of Ukraine’s neighbors — such as Poland and Lithuania — pushed hard for Ukraine to join with Europe: They don’t want a Russian-dominated country on their borders.

Who runs Ukraine?

Yanukovych, the 63-year-old president, is a 6-foot-6-inch politician from the eastern part of the country, close to Russia and home to many Russian speakers. In his youth, he was convicted twice on charges of robbery and assault, which he blamed on youth and adversity. He had to learn the Ukrainian language when he entered the national political scene. He set off the country’s Orange Revolution in 2004, when he won the presidency in a fraudulent election. Ukrainians protested for days until the election was re-run. Yanukovych lost, but Ukrainians were so disappointed with the winner, Viktor Yushchenko, that in 2010 they voted Yanukovych back in. As in Russia, a group of powerful oligarchs who grew rich in the early post-Soviet years exerts a shadowy influence over public life.

What now?

Protesters insist they will stay in the streets until the president resigns. Yanukovych promises no more violence against them. The world can only watch.