Could there ever be another "regime change" war by the US in future?

Afghanistan and Vietnam are reflections of the political war that the US is fighting with itself.

War represents political opportunity. Being for a war will help politicians get elected; being against a war will help politicians get elected. Some politicians play both ends, and that assures them that they will stay politically viable for longer.

Joe Biden voted for the wars in both Iraq and Afghanistan
Hillary Clinton voted for the wars in both Iraq and Afghanistan

We too often reference politicians who were for something before they were against it as just politicians talking from both sides of their mouths. Instead, we should count the casualties between the "for" and "against". As sad as counting the American casualties we need to also count the rest. Millions died in Southeast Asia and likely millions more in Iraq and Afghanistan between the "for" and "against".

Before we again think about regime change elsewhere we need to make a regime change here.

I ask myself what would happen if Taliban-supported terrorists attacked the US again, similar to the 2001 events. How could America possibly react??

history repeats

You underestimate the love for war that conservatives have.

Due to American anti-intellectualism they aren't actually very good at remembering the past or learning their lessons. Remember a sign of being insane is doing the same thing over and over and expecting different results.