BUCHAREST, Romania (AP) - Broken promises of help from the West. A tragic history of Russian invasion that goes back centuries. A painful awareness that conflicts in this volatile region are contagious. These are the factors that make nations across Eastern Europe watch events in Ukraine - and tremble.
From leaders to ordinary people, there is a palpable sense of fear that Russia, seemingly able to thumb its nose at Western powers at will, may seek more opportunities for incursions in its former imperial backyard. The question many people are asking is: Who's next?
"There is first of all fear ... that there could be a possible contagion," Romanian Foreign Minister Titus Corlatean said. "Romania is extremely preoccupied."
AP Photo\People holding Polish and Ukrainian flags listen to speakers during a demonstration in Warsaw, Poland, showing their support for protesters in Ukraine.
Specifically, concerns run high that after taking over the strategic peninsula of Crimea, Russian President Vladimir Putin may be tempted to try a land grab in Moldova, where Russian troops are stationed in the breakaway province of Trans-Dniester. It's one of several "frozen conflicts" across Eastern Europe whose ranks Crimea - many in the West now say with resignation - has joined.
In Romania, which neighbors predominantly Romanian-speaking Moldova, Monica Nistorescu urged the West to stand up to Putin - lest he come to view himself as unbeatable.
"The world should stop seeing Putin as the invincible dragon with silver teeth," said Nistorescu, "because we will succeed in making him believe that Russia is what it once was."
Across the border, Moldovan fears of Russian invasion were in no way theoretical: "We are afraid the conflict in Ukraine could reach us in Moldova," said Victor Cotruta, a clerk in the capital Chisinau. "Russian troops could take over Moldova in a day."
Many in the region are keenly aware that Poland had guarantees of military aid from France and Britain against Nazi aggression. But when Hitler invaded in 1939, France and Britain didn't send troops to Poland despite their declarations of war. That history feeds skepticism that NATO would come to the aid of eastern member nations in the event of a Russian attack.
"Poland's history shows that we should not count on others," novelist Jaroslaw Szulski said.
Such feelings are particularly acute in the Baltic nations that are members of NATO and the European Union. Estonia, Latvia and Lithuania have sizable Russian populations that Moscow periodically declares it needs to "protect" - the key word Putin used in justifying its invasion of Crimea.
"I'm a bit skeptical," said Tiina Seeman in Tallinn, Estonia, when asked if she believed the West would come to her nation's rescue. "I'd like to believe so but I can't say I trust them 100 percent."
Moscow routinely accuses Estonia and Latvia of discriminating against their Russian-speaking minorities. Tensions between Russia and Estonia soared in 2007, when protests by Russian-speakers against the relocation of a Soviet-era war monument ended in street riots. Many Estonians blamed Moscow - which has handed out passports to ethnic Russians in the Baltics - for stirring up the protests.
As she arrived at an EU emergency summit on Ukraine last week, Lithuanian President Dalia Grybauskaite expressed more confidence than Seeman in the U.S.-led security alliance: "Thank God! Thank God that we are already 10 years in NATO!"
But she, too, expressed grave concerns about Russia's actions: "Russia today is trying to rewrite the borders in Europe after World War II."
History weighs heavily in Eastern European minds as they contemplate the future.
Many people see Russia's seizure of Crimea as similar to their experiences after World War II, when Soviet troops rolled through towns and villages, effectively putting them under the Kremlin's rule for decades.
"Of course there's a potential threat for us in the future," Katerina Zapadlova, a waitress in a Prague cafe, said with a bitter smile. She recalled how Soviet troops rolled into Czechoslovakia in 1968 to crush the Prague Spring liberalization movement.
"I'm afraid," she said, "It's because of what they did to us in the past."