Y veamos donde vienen estos problemas :
On April 27, 1978, former Vice General Commander of Afghan Air Force, Wing Commander Abdul Qadir, who held pro-Moscow stand, undertook a coup d'etat, ousted the Daud government and set up "the Democratic Republic of Afghanistan". The Revolutionary Council was established as the highest authority of the country. Mr. Noor Mohammad Taraki, Chairman of the People's Democratic Party became Chairman of the Council and Prime Minister of the government. The new government of Afghanistan sent a memorandum to the Chinese Embassy in Kabul on April 30 and a verbal note to the Chinese Foreign Ministry on May 3 demanding China's recognition of the Afghan government. With a view to further developing the friendly relations between the two countries and two peoples, the Chinese Foreign Ministry replied with a verbal note on May 7 to extend recognition to the new government of Afghanistan. However, soon after this, the Afghan government started to carry out a pro-Soviet Union and anti-China policy by throwing in its own lot with Soviet Union and conducting anti-China activities. Afghanistan also expressed its dissatisfaction to China's establishment of diplomatic ties with the USA.
Osea, que los problemas entre Afganistan-China comienzan cuando el primero, denuncia las relaciones "secretas" entre China y USA. Lo que supuestaemnte es el motivo por el cual el gobierno de Afganistan se posiciona hacia la URSS a partir del 71.

Within the PRC there was also opposition from left-wing elements. This effort was allegedly led by Lin Biao, head of the military, who died in a mysterious plane crash over Mongolia while trying to defect to the Soviet Union. His death silenced most internal dissent over the visit.
Lin Biao, el oficla de mayor rango del Ejercito, muere en un "accidente de avion", se dice que pretendia huir a la URSS.
Both China and the United States backed combatants in Africa against Soviet and Cuban-supported movements. The economic benefits of normalization were slow as it would take decades for American products to penetrate the vast Chinese market. While Nixon's China policy is regarded by many as the highlight of his presidency, others such as William Bundy have argued that it provided very little benefit to the United States.
Anda, China y USA que gozan de unas relaciones diplomaticas de ensueño ( que raro, comunistas y los anticomunistas más radicales como Bzerzsinski de la mano )financian y apoyan a combatientes, contra los socialfascistasimperialistas y sus colonias, es decir, Sovieticos y Cubanos!!! Ya cada vez parece que entiendo más lo que paso en Afganistan.
Liaison Office, 1973–1978
In May 1973, in an effort to build toward formal diplomatic relations, the US and the PRC established the United States Liaison Office (USLO) in Beijing and a counterpart PRC office in Washington, DC. In the years between 1973 and 1978, such distinguished Americans as David K. E. Bruce, George H. W. Bush, Thomas S. Gates, and Leonard Woodcock served as chiefs of the USLO with the personal rank of Ambassador.
President Gerald Ford visited the PRC in 1975 and reaffirmed American interest in normalizing relations with Beijing. Shortly after taking office in 1977, President Jimmy Carter again reaffirmed the goals of the Shanghai Communiqué. Carter's National Security Advisor Zbigniew Brzezinski and senior staff member of the National Security Council Michel Oksenberg encouraged Carter to seek full diplomatic and trade relations with China. Brzezinkski and Oksenberg traveled to Beijing in early 1978 to work with Leonard Woodcock, then head of the liaison office, to lay the groundwork to do so. The United States and the People's Republic of China announced on December 15, 1978 that the two governments would establish diplomatic relations on January 1, 1979
Osea, el mayor anticomunista del estado de USA Zbigniew Brzezinski, anima a Carter a buscar el mayor y total acercamiento a China. Curiosamente el maestro de la operación Cyclon en Afganistan.
In February 1979, the Afghan government delivered a statement condemning China invading Viet Nam. In March, the Afghan government issued another communique accusing China of sending officers to train Afghan guerrillas and providing arms and financial assistance to Afghan refugees in Pakistan. In April, the Afghan media including its newspaper and broadcasting vilified China by alleging that China had trained Afghan "anti-revolutionary elements". The Chinese Foreign Ministry as well as the Chinese Embassy in Kabul made a number of presentations to the Afghan authorities to expose their lies and clarify the truth of events. The Sino-Afghan friendly relations had thus been severely damaged.
El gobierno de Afganistan denuncia a China, por su invasión a Vietnam, despues de la derrota de los Imperialistas yankes. China, por entonces, posiciono 1,500.000 soldados en las fronteras con la URSS por si habia escalada de coflicto al atacar a un aliado de la URSS, osease, Vietnam.
El gobierno de Afganistan, denuncia a China, por enviar supuestamente, a oficiales Chinos a entrenar a las Guerrillas en Afganistan, proveer armamento y apoyo financiero a los refugiados en Pakistan.
On December 25, 1979, the Soviet Union invaded Afghanistan. The Chinese government issued an official statement on December 30 strongly condemning the Soviet Union's armed invasion into Afghanistan. China did not recognize the Karmal regime in Afghanistan which was propped up by the Soviet Union. Therefore, China retained its Embassy in Afghanistan (at the level of Charge d'affaires a.i.), which, however, bore no official relation with the Afghan regime, except some routine work and consular and visa functions.
En definitiva, que China no vuelve a normalizar relaciones con Afganistan hasta que la Republica Democratica de Afganistán Socialista no cae y se impone el Emirato Islamico de Afganistán.
Bien por esos comunistas, que luchan contra los Revisionistas que mayores logros sociales producen en la población, y que luchan en las mismas filas de los islamistas que propician que las mujeres lleven Burkas, en condiciones sociales en el pais que ni siquiera se habian visto en las Monarquias de antes de la Revolución del pais centro asiatico.
lo que puedo entender, es que ese "desastre" analitico en el posicionamiento de esos comunistas , no es tal, y que solo obedece a la geoestrategia politica de China en el teatro a tratar. Solo así se entiende que se luche contra un estado progresista en las filas de las fuerzas más retrogradas y reaccionarias!!
http://en.wikipedia.org/wiki/Sino-American_relations#Rapprochement