In an interview with the Iranian Press TV, Brzezinski described the change in Washington's stance on a variety of national-security objectives under the administration of President Barack Obama.
Speaking on the latest strategy for Afghanistan, which calls for renewed military focus on al-Qaida while vetting moderate elements within the Taliban regime, Brzezinski decoupled the Taliban from the broader issues of terrorism in Afghanistan.
"It may be connected with it by historical circumstances, but Taliban is essentially a specific Afghan phenomenon focused on Afghanistan," he said. "Al-Qaida is an extremist organization which has a variety of very hostile intentions toward a number of countries in the world."
Critics reacted to the Taliban strategy in the plans for Afghanistan, saying the policy of engaging foes to combat greater enemies brought the insurgency and global terrorist threat into existence.
Brzezinski, the national security adviser under President Jimmy Carter, countered that criticism, saying the mujahedin movements in Afghanistan were natural manifestations of the Soviet invasion.
"It was a spontaneous national reaction in Afghanistan," he said. "Supporting it made great sense."
Meanwhile, Brzezinski reacted to Iranian accusations that Washington was more skilled in rhetoric than action in its efforts to move closer to Tehran, saying diplomacy is a two-way street.
"A relationship between serious powers is not built on begging or pleading. If there is a genuine interest in mutual accommodation, actions as well as words, have to be reciprocal," he said.