"Nothing's changed. Even the tanks look the same."

As Ukrainians steel themselves against a full invasion by Russian troops into Crimea, and political leaders across the globe continue trying to reason with President Vladimir Putin so that he quells soldiers and sailors already there, citizens of central and eastern Europe say their mistrust of Russia is as strong as ever.

Czechs and Slovaks, who split peacefully in 1993, "still remember the Russian invasion of 1968", Czech Foreign Minister Lubomir Zaoralek said.

"We all believed that Russia had joined the ranks of civilised countries, so this is a very rude awakening to see that even now, in the 21st century, a country with clearly defined borders can have its territory violated."

Twenty-five years ago, countries stretching from Estonia on the Baltic Sea to Romania along the Black Sea began turning from Soviet-controlled communist regimes into liberal democracies and market economies. Eleven formerly communist nations are now members of both the European Union and Nato.

"The situation evokes historical memories we'd hoped had been put to rest," said Eugeniusz Smolar, a Warsaw-based foreign policy expert who once fled communist Poland.

"It just happens that this historical memory, our own feeling of loneliness and abandonment by our allies, in 1939 for example, all too easily translates into our feelings about Ukraine at the moment."

Janusz Czapinski, a professor of social psychology at Warsaw University, who directs Poland's biggest public opinion survey, said events in Crimea and the 1968 invasion of Czechoslovakia are not necessarily parallel and warned about reading too much of the past into current events.

"That was to some degree a family spat within the Warsaw pact," he said. "Today is different. Poles are not terrified by these events. Perhaps they are near the eastern border, but that is because they fear an influx of refugees, not an invasion."

Even so, with the added security of being part of the world's biggest military and economic alliances, some citizens from Prague to Budapest and Warsaw still fear the ghosts of the past.

For them, the drama playing out in Ukraine shows they have lessons the West has yet to learn.

Russia's actions are "less of a wake-up call and far more a confirmation of what they've been warning about Putin for the past 10 years", said Fredrik Erixon, director of the European Centre for International Political Economy in Brussels.

"Too many western European countries, ranging from Germany to Luxembourg, chose to ignore and play down their fears. The Poles, the Balts and Czechs are now saying, 'I told you so.'"

For most Europeans, those concerns faded in the generation since Russia pulled back from its former satellite region as it invested billions of US dollars to re-establish itself as an economic power across Europe.

Russia offered Ukrainians US$15 billion in aid in December as deadly protests that led to the removal of former President Viktor Yanukovych began.

If Ukraine looks neatly delineated on maps, its often-bloody history is a tangle of invasions and occupations, peoples and beliefs. It is a place that has struggled for centuries to define itself.

Now it finds itself so sharply divided - between support for Russia on one side of the country and loyalty to the West on the other - that it often seems more like two countries than one.

The modern western city of Lviv sees itself at the core of Ukrainian hopes for a more open, democratic government.

But the area, once part of neighbouring Poland and long a wealthy agricultural region, also saw the rise of a series of nationalist movements in the 1930s.

When Germany invaded Ukraine during the second world war, some residents co-operated with the Nazi occupiers, who were seen as liberators from the hated Soviets. When the war ended, Moscow exacted its revenge.

Nationalist fighters who fought Red Army soldiers were killed or sent to prison gulags, along with Roman Catholics and nationalist leaders who could challenge Russian authority.

Watch: Ukraine mobilises army after Russia's threat to invade

Every year thousands of western Ukrainians, some wearing Nazi-themed uniforms, hold rallies honouring men who fought Stalin's forces.

Some political leaders, such as Hungarian Premier Viktor Orban and Czech President Milos Zeman, have publicly supported Russia's increased presence in the region.

Zeman said recently that he foresaw Russia joining the EU in 30 years.

Yesterday, he said closer ties with the EU may be complicated as Russia explains the need to send troops to the neighbouring country as a way to protect the interests of the pro-Russian population in Crimea, which was annexed to Ukraine in 1954 by Soviet leader Nikita Khrushchev.

"Even though I understand the interests of Crimea's Russian-speaking majority … we have our experience with the 1968 Russian military invasion," Zeman told CTK news agency. "I believe any military intervention creates a deep fissure that can't be mended within a single generation."

In Budapest, some Hungarians likened the events in Ukraine to their country's 1956 revolution that the Soviet Union quelled.

Hundreds of residents flocked to the Russian embassy, lighting candles and using them to form the word "UKRAINE" on the street outside.

"We want this region to be peaceful," said 78-year-old Sandor Dusnoki, who said he found himself in the "thick of it" during the revolution and denounced Putin's efforts to influence the region, especially by military means. "The last thing I want is any sort of conflict in the region." Among others, Ukraine shares borders with Poland, Hungary and Slovakia, which joined the EU in 2004, and Romania, which entered in 2007.

Putin, who sought and won lawmakers' approval to use military power in Ukraine, is already known to use force to gain influence in the "near abroad" - his term for former Soviet republics.

In 2008, Russia routed Georgia in a five-day war over the separatist region of South Ossetia, which has since declared its independence from Georgia.

Moldova, on Ukraine's southwest border, also has a proRussian secessionist region, Transnistria.

"All that Putin cares about is realpolitik and spheres of influence to guarantee the rights of Russians and bolster his vision of Russia as a global power," said Spyros Economides, a lecturer in international relations at the London School of Economics.

"This isn't just the ghost of the Soviet Union coming back, but rather that of Russia going back hundreds of years when it ruled or influenced the nations surrounding it. Russia's conception of itself in the world hasn't changed."

In recent months, Polish government officials have played shuttle diplomacy with increasingly sharp criticism of Putin.

"Events in Crimea are a completely unprovoked, duplicitous armed intervention against a sovereign state," said Polish Foreign Minister Radoslaw Sikorski. "Neither Poland nor the world can tolerate this."

An 86-year-old Warsaw resident who lived through the destruction of her city by the Nazis and its political and social domination by Russians, said she had believed Putin would lead a more tolerant Russia.

But Miroslawa, who asked not to give her last name, said as she watched news trucks park in front of the prime minister's office: "Putin is continuing Soviet policy. The situation looks ugly."

Slovak grandmother Ehrnhofer, who now lives in Vienna, can't help but make comparisons with 1968.

The day the tanks came, she was at the local bakery trying to buy bread for her family.

The store was already sold out and the baker ordered her to jump back on her bicycle and ride home.

Still, her parents and some neighbours felt compassion for the soldiers, even as hate for the Soviet system grew, and fed them scarce bread and water.

"Last night, I was looking around my pantry to see whether I have enough food," she said.

"It's a horrible feeling to be living through these flashbacks again."