BERLIN -- By nightfall Saturday, the images of heavily armed Russian troops on the streets of Crimea were evoking simple but terrifying questions around the world: What is the end game for Russian President Vladimir Putin, and who, if anyone, can stop him?
Earlier Saturday, the Russian Parliament had authorized the use of military force in Ukraine, and Russian troops appeared to have taken control of most key locations in the Crimea, a Ukrainian autonomous republic that until 1954 was part of Russia.
But whether Putin intended to deploy troops in other parts of Ukraine, and what would happen if he did was unclear.
There were no reports of resistance to the Russian troops. The Ukrainian Parliament called a meeting for Sunday to consider whether to declare a state of emergency, and Ukraines interim president, Oleksandr Tyrchynov, said hed put the countrys military on alert. But Ukrainian Prime Minister Arseniy Yatsenyuk, in office just two days, was quoted by the English-language Kyiv Post as saying that Ukrainian forces would not resort to force. "We do not make any moves that might provoke a violent confrontation, he said.
In a move seen as a warning not just to the rest of Ukraine but to Western Europe also, the Russian energy giant Gazprom announced that Ukraine owes it $1.5 billion in back payments on natural gas, and that if it isnt paid quickly, the country would lose its now traditional discount. In the past, Russia has cut gas supplies to Ukraine and parts of Western Europe when Putin is trying to make a point.
Unlike the former Soviet republics of Latvia, Lithuania and Estonia, Ukraine is not a member of NATO, so Europe and the United States are not bound by treaty to defend it, and the talk of retaliation from that camp was limited to potential sanctions and diplomatic entreaties which seemed likely to mean little to Russia, where Parliaments approval of military action was unanimous, with no abstentions.
In Washington, the White House announced that President Barack Obama had spent 90 minutes on the telephone with Putin on Saturday, telling the Russian president that he was in violation of international law and urging him to have his troops in Crimea withdraw to Russian bases there and not to enter other parts of the Ukraine. He told Putin that if Russia had concerns about the treatment of ethnic Russians, it should open talks with the Ukrainian government.
In a statement, the White House denounced the Russian movement in Ukraine and said United States was suspending its participation in preparatory meetings for the G-8 to be held in Russia later this year.
"Russia's continued violation of international law will lead to greater political and economic isolation, the statement warned.
Andrey Kolesnikov, a columnist at Moscows Novaya Gazeta, put the context of Saturdays events bluntly: Ukrainians consider the Russian Parliaments vote a declaration of war. They consider Russian forces taking up positions in their territory to be an invasion.
The situation today reminds of 1968 when the decision to intervene in Czechoslovakia was made, he wrote, recalling the Soviet Unions invasion to put down a political reform movement in what was then a member of the Soviet bloc. Even the Soviet rhetoric is back, up to the limited contingent of troops. It seems our government doesnt even have a new dictionary but the old Soviet one.
He concluded, The Olympics are over: Its a free for all now.
Russians downplayed the notion that their actions amounted to anything like a declaration of war. They were simply responding to pleas from ethnic Russians in the Crimea for help in maintaining peace and security in light of the recent chaos that forced Ukrainian President Viktor Yanukovych to flee the country.
Putin cast his request for authorization to send troops as an effort protect Russian lives.
"In connection with the extraordinary situation that has developed in the Ukraine, posing a threat for the lives of citizens of Russia, our compatriots, our forces deployed on the territory of Ukraine (Autonomous Republic of Crimea) in agreement with an international treaty I request approval of the use of armed forces of the Russian Federation on the territory of Ukraine until the socio-political situation is restored in that country," Putins statement said.
At the United Nations, Russian Ambassador Vitaly Churkin made a similar point during an afternoon meeting of the Security Council, noting that one of the first actions of the new government in Kiev had been to downgrade the official status of the Russian language.
Why was that their first action? he asked.
The Russian move appeared to have the support of much of Crimeas population. The local government of Crimean Prime Minister Serhiy Aksyonov voted Saturday not to recognize the authority of the government in Kiev and asked for Russian assistance to protect the region. The Kyiv Post reported that Internet and telephone services to Crimea that had been interrupted for several hours overnight Friday appeared to have returned to normal on Saturday.
Elsewhere in Ukraine, there were pro-Russian demonstrations that sometimes turned violent.
European leaders expressed outrage and scrambled to figure out how to react.
Jose Manuel Barroso, the Portuguese president of the European Commission, called the actions in Crimea unthinkable in the 21st Century on the European continent.
German Chancellor Angela Merkel said everything has to be done these days to protect territorial integrity. But she made no threats of force not surprising given Germanys unfortunate role in Ukraine during World War II.
What we have learned from our history is how important it is that conflicts need to be solved peacefully and diplomatically, she said. This should also be true of the Crimea.
German Foreign Minister Frank-Walter Steinmeier accused Russia of acting provocatively. Anyone who throws more oil on the fire with words or deeds is deliberately pursuing an escalation, he said.
And that may be Putins plan, said Stephen B. Long, a Russia expert at the University of Richmond. Long said Putin was showing off his strength, just as he did in another old Soviet-bloc republic, Georgia, in 2008, where Russian forces quickly overwhelmed the outmatched Georgian military.
Regardless of historical claims and ethnicity, the status quo recognizes Crimea as part of Ukraine, and Putins intervention is unwarranted and illegal, Long wrote in an emailed answer to questions about the crisis. He knows this, but he also knows that the European Union and the United States do not have the stomach for a serious conflict with Russia.
In the years since the Soviet Union collapsed in 1991, NATO membership has expanded deeply into nations formerly considered within the Soviet sphere to include Poland, the Czech Republic, Hungary and Romania, in addition to the three Baltic nations that were once part of the Soviet Union.
But while Ukraine is a NATO partner, a status Russia also holds, it is not a member of the alliance itself and therefore is not entitled to automatic defense in the event of an attack.
NATO Secretary General Anders Fogh Rasmussen said Saturday that members of the Western military alliance were coordinating their responses and urged the Kremlin to show restraint.
Urgent need for de-escalation in Crimea, Rasmussen said in a tweet.
But NATO, whose joint missions in Afghanistan and against Libyas Moammar Gadhafi in recent years have focused far away from the Soviet threat to central Europe for which the group was founded, seemed to have few options.
Long noted that the Russians seemed so at ease with the crisis that they arent even trying hard to excuse it.
Russias rhetoric in defense of its actions is almost comical, with the Russian foreign ministry accusing Ukraine of violently intervening in Crimea, its own territory, and characterizing the Russian forces, the invaders, as acting in self-defense, he wrote.
Masha Gessen, author of a book about Putin, wrote Saturday on the website of the English newspaper The Guardian that Putin had hardly hidden his colonial desires in the past. She noted his oft quoted statement that the collapse of the Soviet Union was the greatest geopolitical catastrophe of our time and also noted a deeply held Russian sense of connection to Crimea.
Crimea, with its sheer cliffs along the Black Sea coast, has long leaned on Russia for support, and is the home of Russias Black Sea Fleet. Many residents yearn for the days of the Soviet empire, a sentiment thought to be especially strong among the thousands of ethnic Russians who were settled in the area by the Soviets, as far back as the rule of Joseph Stalin.
In the days of the Soviet Union, Crimea was the home base for Soviet nuclear subs, and included many large sections that were officially forbidden territory. Workers assigned to the region were obligated to cut off all contacts with anyone not within the community, including family members.
How many Russian troops were already in Crimea before the Russian Parliaments vote is open to debate. Some reports put the number as high as 28,000, though the Ukrainian defense ministry said it was 6,000. The United States told the German government, according to news reports, that it had detected 2,000 troops being flown into Crimea in recent days.
Sympathy for Russia was already high in Crimea in the wake of events in Kiev. About half the population of Crimea is ethnically Russian, and many of its older residents can remember the days before 1954, when then Soviet Premier Nikita Kruschev transferred Crimeas administration from Russia to Ukraine, when both were part of the Soviet Union.
On Friday, Crimean Prime Minister Serhiy Aksyonov, in effect, asked Russia to protect Crimea, claiming control of the military and security forces in his region. On Saturday, the Crimean Parliament furthered that request, noting that they would not recognize the authority of the fledgling Ukrainian government that sprang from the ashes of months of protests.
Russian media was full of exhortations to rush to the aid of our Crimean brothers. That followed days of media coverage in which the protesters in Ukraine were often referred to as fascists and Nazis, recalling the language of World War II to make clear the governments distaste for the protest movement that swept Kiev.
Contributing to this report were Anita Kumar and James Rosen in Washington and Claudia Himmelreich in Berlin.