Certainly, not everyone in Czechoslovakia in 1968 agreed to what the Prague Spring signified. In former international socialist terminology, the opponents began to be called the 'healthy force'. The healthy force started to contemplate international help as early as May. Their feeling was becoming stronger in proportion to their deteriorating position in society. It has to be mentioned, that, with the exception of Romania and of course Tito's Yugoslavia the concept of foreign army intervention could not have survived without other countries of the Eastern Bloc’s loud and public approval of military action. The most prominent advocates were not only Brežněv and his allies but chiefly Ulbricht and Gomulka. Those who pressed for the intervention decided to rely upon the help of the “healthy force” in Czechoslovakia. It is best understood from the announcement of the leader of Hungarian communists, J. Kadár who claimed that, 'it is necessary to find the healthy force within Czechoslovakia, those who are ready to make the request, and that we support it!’
They also feared to be accused as traitors, which is how they ended up
Today it’s well known that signatories of the letter were, according to the sources, ready to hand over the document to the Soviets as soon as Čierná. However, they became afraid; as the Dubček's lobby received massive support from the public on a large scale. There are infamous words which documented that V. Biľak and D.Kolder feared the accusation of betrayal.
Their reservations became truth only a few days later in Bratislava. The letter was received by L. Brežněv.
It would be exaggerating, to say that the letter played a key role in the decisions of the Cremlins hawks on the onset of the military intervention. It did not have that much significance, but it is certain that it played an important part in the plan, especially in the justification of the action. Also, it is interesting that Vasil Biľak, who after all allegedly handing over the letter, had not played a key role in the events that followed. According to researchers, the leader of the traitors was Alois Indra, if only for the fact that his signature was the first in line. It seems that even Brežněv relied on him.
And so it happened, that on the weekend of the 16th and 18th of August, whilst in Moscow the final decision of military action was being made and the General Pavlovskij was appointed the Chief in Command and announcements to the Soviet people, CSSR's citizens and the Czechoslovakian army, that further political and military action was being prepared; members of the group of Indra-Koller met in Orlík. They were there to elaborate a step by step scheme for their ascent to power, which was immediately reported to the Soviet ambassador Černěnko. The scheme announced that on the CC CPC's conference, planned on the 20th August, they would seize the initiative and officially invite the armies-in-waiting. Then they would claim the positions in the Worker-agricultural Provisional Government, and the events were to take shape as they had planned.
Everything seems to confirm that this was the weekend when the Soviet ambassador received the rewritten invitation letter signed by even more people. It was said that there were about fifty signatures, but this seemed to be an exaggeration. The list of all the signatories has not been yet found in any archives.
When and how the letter lost its secrecy
The long searched for 'invitation letter' was discovered on Wendesday 15th of July 1992 by the Chief of the State Archives of the Russian Federation, Rudofl Pichoja, when he was classifying documents in the archives of the President of the USSR. It was in a sealed envelope dated 25/09/1968. The former director of the general department of the CC CCCP and later the General Secretary handwrote on it: 'To be deposited in the archive of the Politburo. Not to be open without permission of Konstantin Černěnko.'
The text of the letter was, in several places, marked by the hand of Leonid Brežněv. Some words were added: for example, 'inclusive of military'. The expression 'leaders of CPSSR and USSR' in the same sentence were corrected to leaders of parties and governments.
It is reasonable to assume that Brežněv asked for a new text of 'the invitation letter' wherein he requested participation in the plan by other countries of the Warsaw Pact.
Rudolf Pichoja informed about his find to the Russian president Boris Jelcin immediately and the latter called Vaclav Havel at 15:40 PM. On Thursday the documents were delivered by a special courier to Prague Castle and the President informed the press that evening.