Xin Jiang is the western province of China with the 10 million Uyghurs of Turkic origin leaving there. During the Soviet invasion of Afghanistan (1979-1989), the Chinese were sending the Uyghurs to their ally Pakistan, the Pakistanis were training them, and they were sending them to fight the Soviets in Afghanistan.
After the end of the Soviet invasion (1989) the Uyghurs went back to Xin Jiang, in 1991 the Soviet Union collapsed, and the countries of Central Asia, which were Russian colonies until 1991, became independent states. China constructed big oil and gas pipelines and started absorbing the oil and gas of the rich in oil and gas Kazakhstan and Turkmenistan.
The Arabs of the Persian Gulf, I guess also the Malaysians and the Indonesians, all of whom count to Asia for their oil and gas exports, created Al Qaeda groups in Xin Jiang, and from these groups the East Turkestan Islamic Movement was created in 1997. East Turkestan Islamic Movement wants an independent and Muslim Xin Jiang.
In 2003 the Americans, the Pakistanis and the Chinese killed the leader of the East Turkestan Islamic Movement Hasan Mahsun, who was hiding in Pakistan. See Hasan Mahsun
Image 1 Hasan Mahsun
Map 1 Xin Jiang
Something similar happened to the Americans. The Americans, together with the Arabs of the Persian Gulf and the Pakistanis, were supporting the Pashtuns of Afghanistan, who were fighting the Soviets too. Most members of the Taliban are Pashtuns. The Iranians were supporting the Tajiks against the Soviets, who are Sunni Muslims but of Iranian origin, and also the Hazaara, who are Shia Muslims and they constitute 20% of the Afghanistan population.
After the the Soviet invasion the Americans wanted to send the oil and gas of Kazakhstan and Turkmenistan to the Indian Ocean, but the Taliban were created, with their members predominantly coming from the Pashtuns. Al Qaeda and the Taliban became allies against the Americans in Afghanistan, with the Taliban taking control of Afghanistan in 1996. Only Pakistan, Saudi Arabia and the United Arab Emirates recognized the Taliban government of the Islamic Emirate of Afghanistan, which was overturned by the American Afghanistan War in 2001.
Map 2 TAPI Pipeline (Turkmenistan-Afghanistan-Pakistan-India)
The 9/11 attack was planned in Afghanistan, by the leader of Al Qaeda (Osama bin Laden) and the leader of the Taliban (Mullah Omar), both heroes of the Afghanistan war against the Soviets. The attack was supported by Iran, Sudan, Iraq, and of course by circles of Saudi Arabia and Pakistan, and from other Arab states of the Persian Gulf.