Denis MacShane: Russian revisionism is our best guide to Putin's priorities

For decades Russia pretended the Germans had killed Poland's leaders

In a remarkable gesture, the German Chancellor Angela Merkel will be in Gdansk today to commemorate the 70 years since a German warship opened fire on Polish soil, thus beginning the Second World War. Her predecessors, Willy Brandt and Helmut Kohl, made symbolic gestures of reconciliation as they sought to acknowledge past evils. Brandt fell to his knees at the Warsaw Ghetto in 1970 and Kohl stretched out and took hold of François Mitterrand's hand at Verdun 15 years later.

In politics, as in life, saying sorry is often the hardest thing to do. Germany has sought to make amends to Poland by supporting Polish entry into Nato and the EU. Despite customary protests from Eurosceptics last week about Britain's help via the EU for Poland and other new EU member states, it is the German taxpayer who pays the lion's share of EU solidarity help to Poland.

The other visitor to Gdansk will be Vladimir Putin. As Russian president and commander-in-chief, Dmitry Medvedev should represent Russia at key international events. But depite it being 20 months since Putin stood down as president he is still clearly in charge. It is Putin who defines the new Russia. So what he has to say at Gdansk is of capital importance. Will he mention the K word?

Katyn was the site of the first major extermination of the Second World War. The Nazi Holocaust, in the sense of the organised and engineered transportation of millions of Jews from all over Europe to be killed in death camps, followed on from the mass shooting of Jews, Roma and others after the invasion of Russia.

But as a single act of extermination, the Russian killing of an estimated 26,000 unarmed prisoner of war officers, lawyers, doctors, professors, civil servants, and journalists who fell into Russian hands after Russia invaded and occupied eastern Poland on 17 September 1939 remains the biggest one-off act of murder in the early part of the war. Andrej Wajda's moving and slow-build film, Katyn (2007), is witness by a great European artist to what happened.

For decades Russia pretended that the extermination of an entire generation of Polish leaders had been carried out by Germans. Sadly, successive British governments accepted this fiction in the belief that appeasing a lie would help promote good relations with the Kremlin.

Will Putin now apologise for this Russian crime against humanity? The signs are not good. He has banned any showing of Katyn in Russia. Moreover, there is now a sustained effort to re-write history by proclaiming the Molotov-Ribbentrop pact which gave the green light to Hitler to invade Poland as a master-stroke of Russian statecraft.

In 1989, under Gorbachev, the Russian Parliament condemned the August 1939 treaty between fascism and communism as "without legal basis". In addition to the partition of Poland between Moscow and Berlin, the Molotov-Ribbentrop pact sanctioned the incorporation of the three Baltic states into the Soviet Union.

Following the Russian invasion and occupation of contested Georgian territory last year and the consequent surge in jingoistic and nationalist fervour, Russian historians, politicians and journalists are finding new merits in the Molotov-Ribbentrop pact. The historian Natalia Narochnitskaya, for example, has argued that the Baltic states and Polish territory occupied by the Red Army were "in the Russian sphere of influence". So that's all right then. Another historian, Pavel Danilin, asserts that the arrival of Russian troops after the Wehrmacht had defeated the Polish army "was not an aggression." Instead it was "about defending the population of a state that had ceased to exist". If this is the official line as nationalist patriotism grows in Russia, the chances of Vladimir Putin using today's Gdansk event to say sorry for Stalin's alliance with Hitler and the annexation of part of Poland as well as the Baltic states are slim.

Saying sorry is risky politics, as those Labour politicians who have dared say British imperialism was noxious find out to their cost. But the Stalin-Hitler deal to re-partition Poland and the cold-blooded killing of prisoners to destroy a nation's educated leadership are two terrible crimes. Is Putin big enough to say sorry? Or does Russian belief that the Ribbentrop-Molotov pact was sound diplomacy tell us what Russian foreign policy in the 21st century will be like?

The author is the Labour MP for Rotherham and was Minister for Europe, 2002-5