The Islamist forces that attacked Uzbekistan after the Taliban came to power in Afghanistan were led by Qari Saifullah Akhtar. Akhtar was educated at the Banuri mosque outside of Karachi which has been much in the news lately. He became head of the Harkat al-Jahad al-Islami movement, and helped the Taliban seize power, and served as an advisor to Mullah Omar. Akhtar's men then served as the spearhead for the aborted invasion of Uzbekistan, an invasion that was supported by Al Qaeda. Later, it was thanks to the US and its presence in Uzbekistan after 9/11 that the country was somewhat stabilized. It was also thanks to the US that Akhtar was traced to the United Arab Emirates; arrested in Dubai in October 2004, he was returned to Pakistan where he was jailed.
Thus it would seem that Uzbekistan seems ungrateful for the US effort. However, the nation itself has joined with Russia, China, and the other "stans" to form an anti-terrorist alliance directed at the region's Islamists. That it has chosen a path separate from the US probably did not surprise anyone with knowledge of the region and its politics.
I think it is tretching things a bit to call the SCO an "anti-terroist alliance."