Poland threw open the doors of its military archives to show how most of Europe would have been laid to waste in a nuclear conflagration between east and west. Dating from 1979, when presidents Jimmy Carter and Leonid Brezhnev were discussing detente, the map showed how Warsaw Pact forces would have responded to an attack by the Nato alliance.

A series of red mushroom clouds over western Europe show that Soviet nuclear weapons strikes would have been launched at Germany, the Netherlands, Denmark and Belgium if Nato had struck first. Red clouds are drawn over the then German capital, Bonn, and other key German cities such as the financial centre of Frankfurt, Cologne, Stuttgart, Munich and the strategically important northern port of Hamburg. Brussels, the political headquarters of Nato, is also targeted. Blue mushroom clouds, representing the expected Nato nuclear strikes, are drawn over cities in the eastern bloc, including Warsaw and the then Czechoslovakian capital, Prague. France would have escaped attack, possibly because it is not a member of Nato's integrated structure. Britain, which has always been at the heart of Nato, would also have been spared, suggesting Moscow wanted to stop at the Rhine to avoid overstretching its forces. The exercise, entitled Seven Days to the River Rhine, indicated Warsaw Pact forces aimed to reach the Franco-German border within a week of a Nato attack.

Standing next to the fading map in Warsaw yesterday, Radoslaw Sikorski, the Polish defence minister, said: "The objective of the exercise on this map is to take over most of western Europe - all of Germany, Belgium and Denmark."

Mr Sikorski, who made a name for himself working for the rightwing American Enterprise Institute thinktank in Washington, made clear he was prepared for a backlash from Russia, whose president, Vladimir Putin, has lamented the demise of the Soviet Union.

Announcing the release of 1,700 Warsaw Pact papers from Poland's military archive, he said: "This is crucial to educating the country on the way Poland was an unwilling ally of the USSR in the cold war. The map shows a classic Warsaw Pact exercise - it was a 'counter' attack to defend itself by going all the way to the Atlantic."

Mr Sikorski, who was appointed after the Law and Justice party won a surprise victory in the recent elections after pledging to cleanse the country of its communist past, believes the map shows how Moscow was prepared to sacrifice Poland to save the Soviet Union.

Nato's policy of retaining the right to a first nuclear strike - because the Soviet Union had far superior conventional forces - meant Polish troops dug in by the River Vistula would have been wiped out.

"This map is a moving and shattering personal experience," Mr Sikorski said of the exercise, which estimated that 2 million Polish civilians would have been killed. "It shows that the Polish army was being used to participate in an operation that would have resulted in the nuclear annihilation of our country."

With ties between Poland and Russia at one of their lowest ebbs since the break-up of the Warsaw Pact, Mr Sikorski was asked whether he feared a Kremlin backlash. He said: "We think the Soviet regime was very detrimental to Russia - the Russian people suffered the most."

Commander Waldemar Wojcik, the head of Poland's Central Military Academy, said: "This was an exercise based on the assumption of a Nato attack. The doctrine of the day was that the Warsaw Pact countries were peace loving." He added: "I visited the Pentagon in 2001 and was shown maps that were the mirror image of this."

Other papers released covered Operation Danube, the invasion of Czechoslovakia in 1968, and details of a massacre of Polish strikers in 1970 at Szczecin which led to the downfall of Wladyslaw Gomulka, the relatively moderate leader.

Kazimierz Marcinkiewicz, the new Polish prime minister, insisted Warsaw was not trying to provoke Russia, even though it released the map without consulting Moscow. "The future should be built on the truth about the past. If the truth is damaging to international relations that is a bad thing ... I am sure this will not spoil our relations with Russia."