The CIA torture program was even bigger than the details released in the Senate Intelligence Committee torture report might suggest. The reason is that the CIA didn't just have its own torture program, run out of its "black site" secret detention and torture prisons broad. It also used a vast network of other countries to help capture, detain, transport, and, yes, torture detainees.
That network is best shown by looking at the CIA's extraordinary rendition program. This is the program under which the CIA would detain and transport suspected terrorists with the help of foreign governments. In all, a stunning 54 countries participated in the CIA-run rendition program. Here they are:
Whether or not all 54 of those countries are complicit in the CIA torture program is debatable. The program could work in a number of different ways; each of these countries supported the CIA's rendition program, but not every country directly participated in torture.
Sometimes the detainees were captured by the CIA with the help of foreign governments, sometimes captured entirely by foreign governments, which would then hand them over. Sometimes they were shipped to CIA-run black sites in foreign countries, and sometimes handed off to foreign intelligence agencies that would detain and torture them in their own facilities. Sometimes, more modestly but still consequentially, friendly foreign governments would help the CIA in finding, arresting, or transporting suspected terrorists.
But the point of this map is that, however vast and shadowy the CIA's torture program was, the agency's associated and often-linked program of extraordinary rendition was even vaster and more shadowy. There is, and will probably forever remain, a great deal about the CIA's post-9/11 programs that is still unknown.