"Something is fundamentally wrong at the heart of US international thinking and understanding. That will be deeply investigated," Prestowitz said.
Asked who Washington may blame for the current situation, Prestowitz replied that he does not think there will be much finger-pointing as it is almost entirely its own fault.
"The US is mostly going to blame itself. Past Presidents, both Democrat and Republican, will mostly be blamed. At a deeper level, there will be a lot of criticism of the US foreign policy elite and of the US military elite. The big question will be: how could our top leaders and policy makers all with top notch education and lots of experience have been so wrong for so long?" he said.
The advance of the Taliban cannot be avoided unless the US sends in a large number of troops, which Biden is not going to do, according to the ex-Reagan adviser.
"I think Biden's decision was fundamentally the right decision. He probably did not understand how quickly the Taliban would be able to take over. Maybe he could have withdrawn more slowly, but that is all speculation. Fundamentally he is doing the right thing for America," he said.
The Taliban's offensive started as soon as the US-led NATO coalition began to leave the country, following a deal between the Trump administration and the Taliban in February 2020 that was later upheld by President Joe Biden.
On Sunday, the Taliban completed their takeover of Afghanistan by entering Kabul without meeting resistance. President Ashraf Ghani resigned and left the country to prevent what he described as bloodshed that would occur if militants had to fight for the city.
Bagram Airfield, which had been the main military base for the US forces in Afghanistan since 2001, is said to have been captured as well. Meanwhile, a Sputnik correspondent reported that almost all TV channels in the country are now broadcasting readings from the Quran or news about the Taliban.
*A terrorist organization banned in Russia