That's why everyone is carefully parsing the words of Russian Prime Minister Vladimir Putin Tuesday at a meeting of European leaders in Gdansk, Poland, to mark the 70th anniversary of the massive Nazi invasion of Poland that triggered World War II.
Standing beside Polish Prime Minister Donald Tusk at the memorial meeting Tuesday, Putin proclaimed that "Russia has always respected the bravery and heroism of the Polish people, soldiers, and officers, who stood up first against Nazism in 1939."
Mr. Putin's not-so-delicate problem is that he unrepentently represents Russia, the successor state of the USSR, which two weeks after the Nazi invasion followed through on a secret agreement with German dictator Adolf Hitler by invading and occupying eastern Poland.
The Russian attack was described Tuesday by Polish President Lech Kaczynski as "a stab in the back ... and this blow came from Bolshevik Russia in accordance with the Molotov-Ribbentrop Pact," the Soviet-German bargain whose secret protocols divided eastern Europe between the two dictatorships.
The Poles were hoping that Putin might apologize for that, and for the subsequent execution of 20,000 Polish military officers, whose burial site in Russia's Katyn Forest has only been officially acknowledged since the collapse of the USSR.
In an open letter Monday to the Polish newspaper Gazeta Wyborcza, Putin went beyond previous official pronouncements by describing the Nazi-Soviet deal as "immoral" and denouncing the mass murder of Polish soldiers by the Soviet NKVD secret police as a "crime."
But Tuesday he dodged an apology and stressed Moscow's view that everyone "made a lot of mistakes" in the prelude to World War II, including the Western allies, who sold out Czechoslovakia to Hitler at Munich in 1938. "As to what preceded the tragedy, that should be left to experts to determine," he said.
The issue of World War II remains so sensitive in eastern Europe because the Molotov-Ribbentrop pact, essentially ratified by the Western allies in subsequent wartime meetings with Joseph Stalin, determined the shape of Europe for more than four decades and left many countries – including Poland – under Soviet control.
"This order lasted until 1989, when the Berlin Wall came down, so it's not ancient history at all," says Pavel Felgenhauer, a security expert with the opposition weekly Novaya Gazeta. "These issues are very real and important to eastern Europeans, and that's why they continue to worry about Moscow's attitude.
Russian experts say Putin probably went as far toward meeting Polish demands as any Kremlin leader could, given that Russia is currently in the midst of an intense domestic battle over the nation's past.
"I think Putin was conciliatory," says Roy Medvedev, one of Russia's leading historians on the Soviet period. "It was a step forward, considering that we haven't had any high-level contacts with Poland for a dozen years."
Mr. Tusk appeared somewhat mollified. "Our meeting [with Putin] showed from the first minute that we are making another step toward strengthening confidence in the past so that we can build our future on it," he said. That future involves better access to Russian gas, on which Poland is dependent for about half its current usage, he made clear.
"Gas must not be used for political gains, but for business interests," Tusk said, adding that he hoped for "the rapid signature" of a contract to construct a new Russian gas pipeline through Poland. Russia's neighbors have repeatedly accused it of using gas supplies as a political weapon.
Whatever progress Putin may have achieved on the historical front in Gdansk Tuesday might have been undone by the publication on the same day of a book of "secret documents" released by Russia's SVR foreign intelligence service.
The volume, entitled "Secrets of Polish Policy 1935-1945," purports to document plans by Poland to join Nazi Germany in an invasion of the USSR in the years before World War II and also details Poland's minor but actual role in the dismemberment of Czechoslovakia following the Munich accord in 1938.
"This is all part of an old Russian game," says Mr. Felgenhauer. "Putin wants to portray himself to the West as a liberal who's surrounded by wolves back in Moscow, but it's really business as usual."