There was a lot of talk that the Russians want access to the Arabian Sea,....even without that, it was not comfortable for Pakistanto effectively share a common border with a hostile Russia known for it's Bear hugs.
Kabul-Moscow agreement of Feb. 28, 1921. It brought under its influence people from every walk of life by different types of deceits and intrigues. During Zahir Shah's reign when Daud Khan was Prime Minister, the Russians were able to prepare the ground for a total change in their benefit by utilizing the means and possibilities left open to them. Zahir sensed the danger. He didn't want to lose his monarchy so soon. Therefore, he forced Daud Khan to resign, and drew up a new Constitution.
But it was too late. The Russians had gotten control of all economic, political and military spheres. The cabinet was shuffled 5 times in less than 10 years. A strange crisis overtook Afghanistan under the name of liberty and democracy. This crisis was created by the Russians for their own benefit. Informed people knew well what a dreadful nightmare threatened Afghanistan. The Russians, who had spread their influence over military and educational systems and had bought up a number of agents, utilized the opportunity offered by the long absence of Zahir Shah. Through officers who were trained for this purpose in Russia, they overthrew the monarchy in a coup d'etat staged under the guidance of Daud Khan who eventually came to power.
Personal complexes of Daud Khan-the mad and ambitious tyrant that he was - and the conspiracies of Russian agents who had gathered around him gave the Russians the opportunity to eliminate a number of talented Afghans inside and outside the army. Thus, the way was paved for their real agents. The Russians used a double faced sword. On the one hand, they wiped out the Islamic and national elements through Daud Khan, and on the other, they made Daud Khan himself hated by the people because of such deeds.
Finally Daud Khan realized it was his turn to be eliminated. Therefore, he tried to save himself by settling the account with his Russian comrades and his coup conspirators. But the Russians did not give him the chance to do so. Once again they acted through their military advisors and Russian trained agents. In a bloody coup d'etat of April 27, 1978 (Saur 7, 1357), the Russians assassinated Daud Khan, and all members of his family. They installed their old-time and trusted agent in power.
In less than two months, the people of Afghanistan realized the true nature of Taraki, and recognized the real coup planners. They rose up and began their Holy Jihad against the puppet government. Because of the anti-human nature of communism, Taraki and his advisors did not hesitate to commit any type of crime and terror in countering this uprising.
Russians learned that resisting the flood of anger and hatred of the Afghan nation was not an easy job. Realizing the situation, they worried about the destruction and down fall of their imposed puppet government,. The Russians called Taraki to Moscow and signed an agreement with him on December 5, 1978. The text of the treaty was not made public but future events as well as the curious remarks made by the Tass news agency, and speeches by Kremlin rulers revealed that the treaty stipulated that Russian troops could enter into Afghanistan in order to break down the heroic resistance of the Afghan people, thus saving the Taraki regime from down-fall.
In the course of these plans and preparations for the occupation of Afghanistan, the Russians decided to play another game hoping to find an opportunity for suppressing the flames of anger and revenge of the Afghan people. They designed a plot for the assassination of Hafizullah Amin. The purpose behind the killing of Amin was to find a scapegoat and blame him for all the murders and catastrophes. Moreover, the Russians wanted to prepare the ground for the return of their old-time spy and genuine slave, namely Babrak Karmal.
Amin. and his criminal band did not hesitate to commit any kind of crime and treason, the truth of the matter was that they acted only within the limits of orders issued by their Russian masters. In fact, they were executioners who received their orders for imprisonment, torture and murders from Moscow.
However, the Russian plot to assassinate Amin failed. The scene of Amin's murder, which was supposed to take place in the presence of Posanov, the Russian Ambassador in Afghanistan, was reversed. Instead of Hafizullah Amin, Taraki himself fell into the trap and was killed a few nights later. The Russians became extremely upset by the failure of their plot. From the very beginning it could be noticed that they would revenge the death of Taraki, and make up for their indignity and humiliation. Sooner or later, Amin's term and life would have been terminated. Amin realized this and tried his best to calm down Russia's anger by pretending to be its loyal and real servant. He tried to raise the slogan of "love of Russia" to the level of "love of motherland" during his term which lasted from September 17, 1979 to December 26, 1979. But Brezhnev was not affected by Amin's servitude and ordered his assassination. Three days before Amin's death, the Red Army with all its arms and ammunitions began to enter Afghanistan. No one knew what was happening. On December 26, Amin was killed in an armed attack directed by General Papitan. The next day Babrak Karmal came to Kabul and was installed as Russia's new puppet.