On 1 December 1980, the Soviets revealed their plans to send in 18 divisions into Poland to put down the Solidarity movement (15 Soviet divisions, 2 Czech division and one E German.) to the deputy chief of the Polish General Staff.
The forces were to enter Poland under the guise of Warsaw Pact maneuvers code named Soyuz 80. But the troops would carry live ammo and move to surround major Polish cities and industrial centers. Four Polish Army divisions were to join latter.
POD: On 5 December 1980, during a meeting of the Warsaw Pact in Moscow, the decision is made for Soyuz 80 to commence because the Soviets do not believe that Jaruzelski, who has suggested his own plan to put down the opposition movement, will be successful. While the risks of intervention are great as are its costs, losing Poland might lead to the unraveling of the entire Eastern Block.
In September, Soviet troops are amassing on Poland's border under cover of military exercize Zapad-81.
Aware of the Soviet troops movements and divisions massing on the Polish border, Zbigniew Brzezinski warns the Soviets that entry of Soviet troops into Poland will be met with a sharp response from the US. The Soviet Ambassador in Washington delivers a response from Moscow: any attempt by the US to intervene militarily will be construed by the Soviet Union as an act of war and be met with a nuclear response.
1 December 1981: Soviet troops enter Poland. The public is told that this is part of Warsaw Pact maneuvers. But Solidarity leadership is told by the CIA that the Soviet troops are carrying live ammo.